The Collaborative International Dictionary of English v.0.48:

So \So\, adv. [OE. so, sa, swa, AS. sw[=a]; akin to OFries,
   s[=a], s?, D. zoo, OS. & OHG. s?, G. so, Icel. sv[=a], sv?,
   svo, so, Sw. s?, Dan. saa, Goth. swa so, sw? as; cf. L. suus
   one's own, Skr. sva one's own, one's self. [root]192. Cf. As,
   Custom, Ethic, Idiom, Such.]
   1. In that manner or degree; as, indicated (in any way), or
      as implied, or as supposed to be known.
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            Why is his chariot so long in coming? --Judges v.
                                                  28.
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   2. In like manner or degree; in the same way; thus; for like
      reason; whith equal reason; -- used correlatively,
      following as, to denote comparison or resemblance;
      sometimes, also, following inasmuch as.
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            As a war should be undertaken upon a just motive, so
            a prince ought to consider the condition he is in.
                                                  --Swift.
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   3. In such manner; to such degree; -- used correlatively with
      as or that following; as, he was so fortunate as to
      escape.
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            I viewed in may mind, so far as I was able, the
            beginning and progress of a rising world. --T.
                                                  Burnet.
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            He is very much in Sir Roger's esteem, so that he
            lives in the family rather as a relation than
            dependent.                            --Addison.
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   4. Very; in a high degree; that is, in such a degree as can
      not well be expressed; as, he is so good; he planned so
      wisely.
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   5. In the same manner; as has been stated or suggested; in
      this or that condition or state; under these
      circumstances; in this way; -- with reflex reference to
      something just asserted or implied; used also with the
      verb to be, as a predicate.
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            Use him [your tutor] with great respect yourself,
            and cause all your family to do so too. --Locke.
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            It concerns every man, with the greatest
            seriousness, to inquire into those matters, whether
            they be so or not.                    --Tillotson.
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            He is Sir Robert's son, and so art thou. --Shak.
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   6. The case being such; therefore; on this account; for this
      reason; on these terms; -- used both as an adverb and a
      conjuction.
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            God makes him in his own image an intellectual
            creature, and so capable of dominion. --Locke.
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            Here, then, exchange we mutually forgiveness;
            So may the guilt of all my broken vows,
            My perjuries to thee, be all forgotten. --Rowe.
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   7. It is well; let it be as it is, or let it come to pass; --
      used to express assent.
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            And when 't is writ, for my sake read it over,
            And if it please you, so; if not, why, so. --Shak.
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            There is Percy; if your father will do me any honor,
            so; if not, let him kill the next Percy himself.
                                                  --Shak.
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   8. Well; the fact being as stated; -- used as an expletive;
      as, so the work is done, is it?
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   9. Is it thus? do you mean what you say? -- with an upward
      tone; as, do you say he refuses? So? [Colloq.]
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   10. About the number, time, or quantity specified;
       thereabouts; more or less; as, I will spend a week or so
       in the country; I have read only a page or so.
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             A week or so will probably reconcile us. --Gay.
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   Note: See the Note under Ill, adv.
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   So . . . as. So is now commonly used as a demonstrative
      correlative of as when it is the puprpose to emphasize the
      equality or comparison suggested, esp. in negative
      assertions, and questions implying a negative answer. By
      Shakespeare and others so . . . as was much used where as
      . . . as is now common. See the Note under As, 1.
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            So do, as thou hast said.             --Gen. xviii.
                                                  5.
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            As a flower of the field, so he flourisheth. --Ps.
                                                  ciii. 15.
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            Had woman been so strong as men.      --Shak.
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            No country suffered so much as England. --Macaulay.
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   So far, to that point or extent; in that particular. "The
      song was moral, and so far was right." --Cowper.

   So far forth, as far; to such a degree. --Shak. --Bacon.

   So forth, further in the same or similar manner; more of
      the same or a similar kind. See And so forth, under
      And.

   So, so, well, well. "So, so, it works; now, mistress, sit
      you fast." --Dryden. Also, moderately or tolerably well;
      passably; as, he succeeded but so so. "His leg is but so
      so." --Shak.

   So that, to the end that; in order that; with the effect or
      result that.

   So then, thus then it is; therefore; the consequence is.
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The Collaborative International Dictionary of English v.0.48:

So \So\, conj.
   Provided that; on condition that; in case that; if.
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         Though all the winds of doctrine were let loose play
         upon the earth, so truth be in the field, we do
         injuriously, by licensing and prohibiting, to misdoubt
         her strength.                            --Milton.
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The Collaborative International Dictionary of English v.0.48:

So \So\, interj.
   Be as you are; stand still; stop; that will do; right as you
   are; -- a word used esp. to cows; also used by sailors.
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The Collaborative International Dictionary of English v.0.48:

Thionyl \Thi"on*yl\, n. [Thionic + -yl.] (Chem.)
   The hypothetical radical SO, regarded as an essential
   constituent of certain sulphurous compounds; as, thionyl
   chloride.
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WordNet (r) 3.0 (2006):

so
    adv 1: to a very great extent or degree; "the idea is so
           obvious"; "never been so happy"; "I love you so"; "my
           head aches so!"
    2: in a manner that facilitates; "he observed the snakes so he
       could describe their behavior"; "he stooped down so he could
       pick up his hat"
    3: in such a condition or manner, especially as expressed or
       implied; "They're happy and I hope they will remain so"; "so
       live your life that old age will bring no regrets"
    4: to a certain unspecified extent or degree; "I can only go so
       far with this student"; "can do only so much in a day"
    5: in the same way; also; "I was offended and so was he";
       "worked hard and so did she"
    6: in the way indicated; "hold the brush so"; "set up the pieces
       thus"; (`thusly' is a nonstandard variant) [syn: thus,
       thusly, so]
    7: (usually followed by `that') to an extent or degree as
       expressed; "he was so tired he could hardly stand"; "so dirty
       that it smells"
    8: subsequently or soon afterward (often used as sentence
       connectors); "then he left"; "go left first, then right";
       "first came lightning, then thunder"; "we watched the late
       movie and then went to bed"; "and so home and to bed" [syn:
       then, so, and so, and then]
    9: (used to introduce a logical conclusion) from that fact or
       reason or as a result; "therefore X must be true"; "the eggs
       were fresh and hence satisfactory"; "we were young and thence
       optimistic"; "it is late and thus we must go"; "the witness
       is biased and so cannot be trusted" [syn: therefore,
       hence, thence, thus, so]
    10: in truth (often tends to intensify); "they said the car
        would break down and indeed it did"; "it is very cold
        indeed"; "was indeed grateful"; "indeed, the rain may still
        come"; "he did so do it!" [syn: indeed, so]
    n 1: the syllable naming the fifth (dominant) note of any
         musical scale in solmization [syn: sol, soh, so]

The Free On-line Dictionary of Computing (19 January 2023):

SO

   1.  Shift Out

   2. Significant Other, almost invariably written abbreviated
   and pronounced /S-O/ by hackers.  Used to refer to one's
   primary relationship, especially a live-in to whom one is not
   married.

   [Jargon File]


The Free On-line Dictionary of Computing (19 January 2023):

so

    The country code for Somalia.

   (1999-01-27)


The Jargon File (version 4.4.7, 29 Dec 2003):

SO
 /S·O/, n.

    1. (also S.O.) Abbrev. for Significant Other, almost invariably written
    abbreviated and pronounced /S·O/ by hackers. Used to refer to one's primary
    relationship, esp. a live-in to whom one is not married. See MOTAS, 
    MOTOS, MOTSS.

    2. [techspeak] The Shift Out control character in ASCII (Control-N,
    0001110).