The Collaborative International Dictionary of English v.0.48:

Aye \Aye\, n.
   An affirmative vote; one who votes in the affirmative; as,
   "To call for the ayes and noes;" "The ayes have it."
   [1913 Webster] Aye

The Collaborative International Dictionary of English v.0.48:

Aye \Aye\, Ay \Ay\, adv. [Icel. ei, ey; akin to AS. [=a],
   [=a]wa, always, Goth. aiws an age, Icel. [ae]fi, OHG, ?wa, L.
   aevum, Gr. ? an age, ?, ?, ever, always, G. je, Skr. ?va
   course. ?, ?. Cf. Age, v., Either, a., Or, conj.]
   Always; ever; continually; for an indefinite time.
   [1913 Webster]

         For his mercies aye endure.              --Milton.
   [1913 Webster]

   For aye, always; forever; eternally.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Aye \Aye\, Ay \Ay\, adv. [Perh. a modification of yea, or from
   the interjection of admiration or astonishment, OE. ei, ey,
   why, hey, ay, well, ah, ha. Cf. MHG. & G. ei, Dan. ej. Or
   perh. akin to aye ever.]
   Yes; yea; -- a word expressing assent, or an affirmative
   answer to a question. It is much used in viva voce voting in
   legislative bodies, etc.
   [1913 Webster]

   Note: This word is written I in the early editions of
         Shakespeare and other old writers.
         [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

96 Moby Thesaurus words for "aye":
   Australian ballot, Hare system, OK, acceptance, accord,
   acquiescence, affirmation, affirmative, affirmative attitude,
   affirmative voice, affirmativeness, agreed, agreement, amen,
   approbation, approval, assent, ballot, blessing, canvass,
   canvassing, casting vote, compliance, con, connivance, consent,
   counting heads, cumulative voting, deciding vote, division,
   eagerness, endorsement, enfranchisement, fagot vote, franchise,
   graveyard vote, hand vote, interest, list system, nay, no, nod,
   nod of assent, nontransferable vote, okay, permission, plebiscite,
   plebiscitum, plumper, plural vote, poll, polling,
   preferential voting, pro, promptitude, promptness,
   proportional representation, proxy, ratification, readiness,
   record vote, referendum, representation, right to vote,
   rising vote, sanction, say, secret ballot, show of hands, side,
   single vote, snap vote, straw vote, submission, suffrage,
   the affirmative, the negative, thumbs-up, transferable vote,
   ungrudgingness, unloathness, unreluctance, viva voce, voice,
   voice vote, vote, voting, voting right, willingness, write-in,
   write-in vote, yea, yea-saying, yeas and nays, yep, yes