The Collaborative International Dictionary of English v.0.48:

Wench \Wench\ (w[e^]nch), v. i. [imp. & p. p. Wenched
   (w[e^]ncht); p. pr. & vb. n. Wenching.]
   To frequent the company of wenches, or women of ill fame.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Wench \Wench\ (w[e^]nch), n. [OE. wenche, for older wenchel a
   child, originally, weak, tottering; cf. AS. wencle a maid, a
   daughter, wencel a pupil, orphan, wincel, winclu, children,
   offspring, wencel weak, wancol unstable, OHG. wanchol;
   perhaps akin to E. wink. See Wink.]
   [1913 Webster]
   1. A young woman; a girl; a maiden. --Shak.
      [1913 Webster]

            Lord and lady, groom and wench.       --Chaucer.
      [1913 Webster]

            That they may send again
            My most sweet wench, and gifts to boot. --Chapman.
      [1913 Webster]

            He was received by the daughter of the house, a
            pretty, buxom, blue-eyed little wench. --W. Black.
      [1913 Webster]

   2. A low, vicious young woman; a drab; a strumpet.
      [1913 Webster]

            She shall be called his wench or his leman.
                                                  --Chaucer.
      [1913 Webster]

            It is not a digression to talk of bawds in a
            discourse upon wenches.               --Spectator.
      [1913 Webster]

   3. A colored woman; a negress. [Archaic, U. S.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

wench
    n 1: informal terms for a (young) woman [syn: dame, doll,
         wench, skirt, chick, bird]
    v 1: frequent prostitutes

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "wench":
   Jane, Jezebel, abigail, amah, au pair girl, ayah, babe, baby,
   bad woman, baggage, betweenmaid, biddy, bird, bitch, broad,
   chambermaid, chaperon, chick, chippy, clitoromaniac, cocotte,
   colleen, companion, cook, cutie, dame, damoiselle, damsel,
   demoiselle, doll, drab, duenna, easy lay, easy woman,
   femme de chambre, fille de chambre, filly, floozy, frail,
   frail sister, gal, gentlewoman, girl, girlie, grisette, handmaid,
   handmaiden, harridan, heifer, hen, hired girl, housemaid, hoyden,
   hussy, hysteromaniac, jade, jeune fille, jezebel, jill,
   junior miss, kitchenmaid, lady-help, lady-in-waiting, lass, lassie,
   little missy, live-in maid, live-out maid, loose woman,
   mademoiselle, maid, maiden, maidservant, minx, miss, missy,
   nursemaid, nymphet, nympho, nymphomaniac, parlormaid, pickup,
   piece, quail, quean, romp, schoolgirl, schoolmaid, schoolmiss,
   scullery maid, servant girl, servitress, skirt, slattern, slip,
   slut, soubrette, strumpet, subdeb, subdebutante, subteen,
   subteener, tart, teenybopper, tomato, tomboy, tramp, trollop,
   trull, tweeny, upstairs maid, uteromaniac, virgin, waiting maid,
   wanton, whore, young creature, young thing