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