The Collaborative International Dictionary of English v.0.48:

Be \Be\ (b[=e]), v. i. [imp. Was (w[o^]z); p. p. Been
   (b[i^]n); p. pr. & vb. n. Being.] [OE. been, beon, AS.
   be['o]n to be, be['o]m I am; akin to OHG. bim, pim, G. bin, I
   am, Gael. & Ir. bu was, W. bod to be, Lith. bu-ti, O. Slav.
   by-ti, to be, L. fu-i I have been, fu-turus about to be,
   fo-re to be about to be, and perh. to fieri to become, Gr.
   fy^nai to be born, to be, Skr. bh[=u] to be. This verb is
   defective, and the parts lacking are supplied by verbs from
   other roots, is, was, which have no radical connection with
   be. The various forms, am, are, is, was, were, etc., are
   considered grammatically as parts of the verb "to be", which,
   with its conjugational forms, is often called the substantive
   verb. [root]97. Cf. Future, Physic.]
   1. To exist actually, or in the world of fact; to have
      existence.
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            To be contents his natural desire.    --Pope.
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            To be, or not to be: that is the question. --Shak.
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   2. To exist in a certain manner or relation, -- whether as a
      reality or as a product of thought; to exist as the
      subject of a certain predicate, that is, as having a
      certain attribute, or as belonging to a certain sort, or
      as identical with what is specified, -- a word or words
      for the predicate being annexed; as, to be happy; to be
      here; to be large, or strong; to be an animal; to be a
      hero; to be a nonentity; three and two are five;
      annihilation is the cessation of existence; that is the
      man.
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   3. To take place; to happen; as, the meeting was on Thursday.
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   4. To signify; to represent or symbolize; to answer to.
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            The field is the world.               --Matt. xiii.
                                                  38.
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            The seven candlesticks which thou sawest are the
            seven churches.                       --Rev. i. 20.
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   Note: The verb to be (including the forms is, was, etc.) is
         used in forming the passive voice of other verbs; as,
         John has been struck by James. It is also used with the
         past participle of many intransitive verbs to express a
         state of the subject. But have is now more commonly
         used as the auxiliary, though expressing a different
         sense; as, "Ye have come too late -- but ye are come. "
         "The minstrel boy to the war is gone." The present and
         imperfect tenses form, with the infinitive, a
         particular future tense, which expresses necessity,
         duty, or purpose; as, government is to be supported; we
         are to pay our just debts; the deed is to be signed
         to-morrow.
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   Note: Have or had been, followed by to, implies movement. "I
         have been to Paris." --Sydney Smith. "Have you been to
         Franchard ?" --R. L. Stevenson.
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   Note: Been, or ben, was anciently the plural of the
         indicative present. "Ye ben light of the world."
         --Wyclif, Matt. v. 14. Afterwards be was used, as in
         our Bible: "They that be with us are more than they
         that be with them." --2 Kings vi. 16. Ben was also the
         old infinitive: "To ben of such power." --R. of
         Gloucester. Be is used as a form of the present
         subjunctive: "But if it be a question of words and
         names." --Acts xviii. 15. But the indicative forms, is
         and are, with if, are more commonly used.
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   Be it so, a phrase of supposition, equivalent to suppose it
      to be so; or of permission, signifying let it be so.
      --Shak.

   If so be, in case.

   To be from, to have come from; as, from what place are you?
      I am from Chicago.

   To let be, to omit, or leave untouched; to let alone. "Let
      be, therefore, my vengeance to dissuade." --Spenser.
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   Syn: To be, Exist.

   Usage: The verb to be, except in a few rare cases, like that
          of Shakespeare's "To be, or not to be", is used simply
          as a copula, to connect a subject with its predicate;
          as, man is mortal; the soul is immortal. The verb to
          exist is never properly used as a mere copula, but
          points to things that stand forth, or have a
          substantive being; as, when the soul is freed from all
          corporeal alliance, then it truly exists. It is not,
          therefore, properly synonymous with to be when used as
          a copula, though occasionally made so by some writers
          for the sake of variety; as in the phrase "there
          exists [is] no reason for laying new taxes." We may,
          indeed, say, "a friendship has long existed between
          them," instead of saying, "there has long been a
          friendship between them;" but in this case, exist is
          not a mere copula. It is used in its appropriate sense
          to mark the friendship as having been long in
          existence.
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