The Collaborative International Dictionary of English v.0.48:

Stay \Stay\ (st[=a]), n. [AS. staeg, akin to D., G., Icel., Sw.,
   & Dan. stag; cf. OF. estai, F. ['e]tai, of Teutonic origin.]
   (Naut.)
   A large, strong rope, employed to support a mast, by being
   extended from the head of one mast down to some other, or to
   some part of the vessel. Those which lead forward are called
   fore-and-aft stays; those which lead to the vessel's side are
   called backstays. See Illust. of Ship.
   [1913 Webster]

   In stays, or Hove in stays (Naut.), in the act or
      situation of staying, or going about from one tack to
      another. --R. H. Dana, Jr.

   Stay holes (Naut.), openings in the edge of a staysail
      through which the hanks pass which join it to the stay.

   Stay tackle (Naut.), a tackle attached to a stay and used
      for hoisting or lowering heavy articles over the side.

   To miss stays (Naut.), to fail in the attempt to go about.
      --Totten.

   Triatic stay (Naut.), a rope secured at the ends to the
      heads of the foremast and mainmast with thimbles spliced
      to its bight into which the stay tackles hook.
      [1913 Webster]