The Collaborative International Dictionary of English v.0.48:

Bless \Bless\, v. t. [imp. & p. p. Blessedor Blest; p. pr. &
   vb. n. Blessing.] [OE. blessien, bletsen, AS. bletsian,
   bledsian, bloedsian, fr. bl?d blood; prob. originally to
   consecrate by sprinkling with blood. See Blood.]
   1. To make or pronounce holy; to consecrate
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            And God blessed the seventh day, and sanctified it.
                                                  --Gen. ii. 3.
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   2. To make happy, blithesome, or joyous; to confer prosperity
      or happiness upon; to grant divine favor to.
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            The quality of mercy is . . . twice blest;
            It blesseth him that gives and him that takes.
                                                  --Shak.
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            It hath pleased thee to bless the house of thy
            servant, that it may continue forever before thee.
                                                  --1 Chron.
                                                  xvii. 27 (R.
                                                  V. )
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   3. To express a wish or prayer for the happiness of; to
      invoke a blessing upon; -- applied to persons.
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            Bless them which persecute you.       --Rom. xii.
                                                  14.
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   4. To invoke or confer beneficial attributes or qualities
      upon; to invoke or confer a blessing on, -- as on food.
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            Then he took the five loaves and the two fishes, and
            looking up to heaven, he blessed them. --Luke ix.
                                                  16.
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   5. To make the sign of the cross upon; to cross (one's self).
      [Archaic] --Holinshed.
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   6. To guard; to keep; to protect. [Obs.]
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   7. To praise, or glorify; to extol for excellences.
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            Bless the Lord, O my soul: and all that is within
            me, bless his holy name.              --Ps. ciii. 1.
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   8. To esteem or account happy; to felicitate.
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            The nations shall bless themselves in him. --Jer.
                                                  iv. 3.
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   9. To wave; to brandish. [Obs.]
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            And burning blades about their heads do bless.
                                                  --Spenser.
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            Round his armed head his trenchant blade he blest.
                                                  --Fairfax.
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   Note: This is an old sense of the word, supposed by Johnson,
         Nares, and others, to have been derived from the old
         rite of blessing a field by directing the hands to all
         parts of it. "In drawing [their bow] some fetch such a
         compass as though they would turn about and bless all
         the field." --Ascham.
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   Bless me! Bless us! an exclamation of surprise. --Milton.

   To bless from, to secure, defend, or preserve from. "Bless
      me from marrying a usurer." --Shak.
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            To bless the doors from nightly harm. --Milton.
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   To bless with, To be blessed with, to favor or endow
      with; to be favored or endowed with; as, God blesses us
      with health; we are blessed with happiness.
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WordNet (r) 3.0 (2006):

bless
    v 1: give a benediction to; "The dying man blessed his son"
         [ant: anathemise, anathemize, bedamn, beshrew,
         curse, damn, imprecate, maledict]
    2: confer prosperity or happiness on
    3: make the sign of the cross over someone in order to call on
       God for protection; consecrate [syn: bless, sign]
    4: render holy by means of religious rites [syn: consecrate,
       bless, hallow, sanctify] [ant: deconsecrate,
       desecrate, unhallow]

Moby Thesaurus II by Grady Ward, 1.0:

141 Moby Thesaurus words for "bless":
   OK, accept, acknowledge, admire, adore, adulate, apotheosize,
   approve, approve of, arm, armor, beatify, belaud, bepraise,
   bless the Lord, bless with, blow up, boast of, brag about,
   canonize, celebrate, champion, cheer, cleanse, cloak,
   compass about, compliment, congratulate, consecrate, copyright,
   countenance, cover, credit, cross, cry up, cushion, dedicate,
   defend, deify, devote, dower, doxologize, emblazon, endorse, endow,
   endow with, enshrine, ensure, esteem, eulogize, exalt, extol,
   favor, favor with, felicitate, fence, fend, flatter, furnish, give,
   give benediction, give credit, give thanks, gladden, glorify,
   glorify the Lord, grace, grace with, gratulate, guarantee, guard,
   hallow, happify, harbor, haven, hero-worship, hold with, hymn,
   idolize, insure, invest, invoke benefits upon, keep,
   keep from harm, keep in countenance, laud, lay hands on, lionize,
   magnify, make acknowledgments of, make happy, make much of,
   make safe, nestle, offer thanks, overpraise, panegyrize, patent,
   pay tribute, police, porter aux nues, praise, praise God, protect,
   provide, puff, puff up, purify, recognize, register, rejoice with,
   render credit, render thanks, respect, return thanks, revere,
   ride shotgun for, safeguard, saint, salute, sanctify, sanction,
   screen, secure, set apart, settle on, settle upon, shelter, shield,
   shroud, sing praises, supply, take kindly to, thank, think well of,
   trumpet, underwrite, uphold, vest, vest with, view with favor



Easton's 1897 Bible Dictionary:

Bless
   (1.) God blesses his people when he bestows on them some gift
   temporal or spiritual (Gen. 1:22; 24:35; Job 42:12; Ps. 45:2;
   104:24, 35).

     (2.) We bless God when we thank him for his mercies (Ps.
   103:1, 2; 145:1, 2).

     (3.) A man blesses himself when he invokes God's blessing
   (Isa. 65:16), or rejoices in God's goodness to him (Deut. 29:19;
   Ps. 49:18).

     (4.) One blesses another when he expresses good wishes or
   offers prayer to God for his welfare (Gen. 24:60; 31:55; 1 Sam.
   2:20). Sometimes blessings were uttered under divine
   inspiration, as in the case of Noah, Isaac, Jacob, and Moses
   (Gen. 9:26, 27; 27:28, 29, 40; 48:15-20; 49:1-28; Deut. 33). The
   priests were divinely authorized to bless the people (Deut.
   10:8; Num. 6:22-27). We have many examples of apostolic
   benediction (2 Cor. 13:14; Eph. 6:23, 24; 2 Thess. 3:16, 18;
   Heb. 13:20, 21; 1 Pet. 5:10, 11).

     (5.) Among the Jews in their thank-offerings the master of the
   feast took a cup of wine in his hand, and after having blessed
   God for it and for other mercies then enjoyed, handed it to his
   guests, who all partook of it. Ps. 116:13 refers to this custom.
   It is also alluded to in 1 Cor. 10:16, where the apostle speaks
   of the "cup of blessing."