The Collaborative International Dictionary of English v.0.48:

Unenterprising \Unenterprising\
   See enterprising.

WordNet (r) 3.0 (2006):

unenterprising
    adj 1: lacking in enterprise; not bold or venturesome [syn:
           unenterprising, nonenterprising] [ant:
           enterprising]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "unenterprising":
   bone-lazy, cadging, canny, careful, cautious, circumspect,
   deliberate, dilatory, discreet, do-nothing, doless, dronish, drony,
   easy, ergophobic, faineant, gingerly, good-for-nothing, guarded,
   heedful, hesitant, indolent, judicious, laggard, lax, lazy,
   leaving out nothing, mindful, nonaggressive, noncommittal,
   on guard, overlooking no possibility, parasitic, pawky, politic,
   procrastinative, prudent, regardful, remiss, safe, scrounging,
   shiftless, slack, slothful, slow, slow to act, sponging, tentative,
   thorough, unadventurous, uncommunicative, undaring, unprecipitate,
   work-shy