The Collaborative International Dictionary of English v.0.48:

Squeamish \Squeam"ish\ (skw[=e]m"[i^]sh), a. [OE. squaimous,
   sweymous, probably from OE. sweem, swem, dizziness, a
   swimming in the head; cf. Icel. sveimr a bustle, a stir,
   Norw. sveim a hovering about, a sickness that comes upon one,
   Icel. svimi a giddiness, AS. sw[imac]ma. The word has been
   perhaps confused with qualmish. Cf. Swim to be dizzy.]
   Having a stomach that is easily turned or nauseated; hence,
   nice to excess in taste; fastidious; easily disgusted; apt to
   be offended at trifling improprieties.
   [1913 Webster]

         Quoth he, that honor's very squeamish
         That takes a basting for a blemish.      --Hudibras.
   [1913 Webster]

         His muse is rustic, and perhaps too plain
         The men of squeamish taste to entertain. --Southern.
   [1913 Webster]

         So ye grow squeamish, Gods, and sniff at heaven. --M.
                                                  Arnold.
   [1913 Webster]

   Syn: Fastidious; dainty; overnice; scrupulous. See
        Fastidious.
        [1913 Webster] -- Squeam"ish*ly, adv. --
        Squeam"ish*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

squeamish
    adj 1: excessively fastidious and easily disgusted; "too nice
           about his food to take to camp cooking"; "so squeamish he
           would only touch the toilet handle with his elbow" [syn:
           dainty, nice, overnice, prissy, squeamish]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "squeamish":
   airsick, barfy, bashful, boggling, carsick, critical, dainty,
   delicate, demanding, demurring, difficult, diffident, dizzy,
   exacting, faltering, fastidious, finical, finicking, finicky,
   finikin, fuddy-duddy, fuss-budgety, fussy, hard to please,
   hesitant, hesitating, meticulous, modest, nauseated, nauseous,
   nice, painstaking, particular, pawky, pernickety, persnickety,
   prudish, pukish, puky, punctilious, qualmish, qualmy, queasy,
   queer, scrupulous, seasick, shaky, shrinking, shy, stickling,
   unsettled, upset, vertiginous