Source : Webster's Revised Unabridged Dictionary (1913)

Boon \Boon\, a. [F. bon. See {Boon}, n.]
   1. Good; prosperous; as, boon voyage. [Obs.]

   2. Kind; bountiful; benign.

            Which . . . Nature boon Poured forth profuse on
            hill, and dale, and plain.            --Milton.

   3. Gay; merry; jovial; convivial.

            A boon companion, loving his bottle.  --Arbuthnot.

Boon \Boon\, n. [Scot. boon, bune, been, Gael. & Ir. bunach
   coarse tow, fr. bun root, stubble.]
   The woody portion flax, which is separated from the fiber as
   refuse matter by retting, braking, and scutching.

Boon \Boon\ (b[=oo]n), n. [OE. bone, boin, a petition, fr. Icel.
   b[=o]n; akin to Sw. & Dan. b[aum]n, AS. b[=e]n, and perh. to
   E. ban; but influenced by F. bon good, fr. L. bonus.
   [root]86. See 2d {Ban}, {Bounty}.]
   1. A prayer or petition. [Obs.]

            For which to God he made so many an idle boon.
                                                  --Spenser.

   2. That which is asked or granted as a benefit or favor; a
      gift; a benefaction; a grant; a present.

            Every good gift and every perfect boon is from
            above.                                --James i. 17
                                                  (Rev. Ver. ).

Source : WordNet®

boon
     adj : very close and convivial; "boon companions"

boon
     n : a desirable state; "enjoy the blessings of peace"; "a
         spanking breeze is a boon to sailors" [syn: {blessing}]