WordNet (r) 3.0 (2006):

sissified
    adj 1: having unsuitable feminine qualities [syn: effeminate,
           emasculate, epicene, cissy, sissified,
           sissyish, sissy]

Moby Thesaurus II by Grady Ward, 1.0:

72 Moby Thesaurus words for "sissified":
   afraid, breakable, brittle, cheap-jack, chicken, chickenhearted,
   cobwebby, coward, cowardly, cowed, crumbly, dainty, daunted,
   delicate, delicately weak, dismayed, effeminate, epicene,
   fainthearted, fearful, flimsy, fragile, frail, frangible, funking,
   funky, gimcrack, gimcracky, gossamery, henhearted, intimidated,
   jerry, jerry-built, light, lightweight, lily-livered, milk-livered,
   milksoppish, milksoppy, mousy, muliebrous, namby-pamby,
   old-womanish, overtimid, overtimorous, panic-prone, panicky,
   papery, pasteboardy, pigeonhearted, prissy, puny, rabbity,
   shattery, sissy, sissyish, sleazy, slight, soft, tacky, timid,
   timorous, unmanly, unmanned, unsubstantial, weak, weak-kneed,
   weakhearted, white-livered, wispy, womanish, yellow