NOUN (1)

1. something to which a mountain climber's rope can be secured;


VERB (2)

1. turn a rope round an object or person in order to secure it or him;

2. fasten a boat to a bitt, pin, or cleat;

The Collaborative International Dictionary of English v.0.48:

Belay \Be*lay"\, v. t. [imp. & p. p. Belaid, Belayed; p. pr.
   & vb. n. Belaying.] [For senses 1 & 2, D. beleggen to
   cover, belay; akin to E. pref. be-, and lay to place: for
   sense 3, OE. beleggen, AS. belecgan. See pref. Be-, and
   Lay to place.]
   1. To lay on or cover; to adorn. [Obs.]
      [1913 Webster]

            Jacket . . . belayed with silver lace. --Spenser.
      [1913 Webster]

   2. (Naut.) To make fast, as a rope, by taking several turns
      with it round a pin, cleat, or kevel. --Totten.
      [1913 Webster]

   3. To lie in wait for with a view to assault. Hence: to block
      up or obstruct. [Obs.] --Dryden.
      [1913 Webster]

   Belay thee! Stop.
      [1913 Webster]

WordNet (r) 3.0 (2006):

belay
    n 1: something to which a mountain climber's rope can be secured
    v 1: turn a rope round an object or person in order to secure it
         or him
    2: fasten a boat to a bitt, pin, or cleat

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "belay":
   abandon, abort, affix, anchor, annex, attach, batten, batten down,
   cancel, cease, cement, chain, cinch, clamp, clinch, cramp,
   cut it out, desist, discontinue, drop it, end, engraft, fasten,
   fasten down, fix, give over, graft, grapple, halt, have done with,
   hold, knit, knock it off, lay off, leave off, make fast,
   make secure, make sure, moor, put to, quit, refrain, relinquish,
   renounce, screw up, scrub, secure, set, set to, stay, stop,
   terminate, tether, tie, tighten, trice up, trim