Source : Webster's Revised Unabridged Dictionary (1913)

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.

         For his mercies aye endure.              --Milton.

   {For aye}, {always}; forever; eternally.

Ay \Ay\, interj.
   Ah! alas! ``Ay me! I fondly dream `Had ye been there.'''
   --Milton.

Ay \Ay\, adv.
   Same as {Aye}.

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.

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