The Collaborative International Dictionary of English v.0.48:

Ye \Y"["e]\ ([=e]"e), n.; pl. Y["e]n ([=e]"en).
   An eye. [Obs.]
   [1913 Webster]

         From his y["e]n ran the water down.      --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Yen \Yen\, n.
   The unit of value and account in Japan. The yen is equal to
   100 sen. From Japan's adoption of the gold standard, in 1897,
   to about 1913 the value of the yen was about 50 cents. In
   1997 and 1998 the value of the yen varied from 80 per U. S.
   dollar to 120 per dollar.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

yen
    n 1: a yearning for something or to do something [syn:
         hankering, yen]
    2: the basic unit of money in Japan; equal to 100 sen
    v 1: have a desire for something or someone who is not present;
         "She ached for a cigarette"; "I am pining for my lover"
         [syn: ache, yearn, yen, pine, languish]

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "yen":
   Deutschmark, Heimweh, Mark, Reichsmark, ache, aching, afghani,
   anna, baht, cent, centavo, centime, conto, crave, desiderium,
   dollar, dong, florin, franc, guilder, gulden, hanker, hankering,
   homesickness, honing, hunger, kip, kopeck, krona, krone,
   languishing, languishment, lira, longing, lust, mal du pays,
   maladie du pays, milreis, nostalgia, nostomania, peseta, pie,
   piece of eight, pine, pining, pistareen, pound, rand, rial, ruble,
   rupee, shekel, shilling, sigh, sol, sou, stiver, thirst, won,
   yearn, yearning