The Collaborative International Dictionary of English v.0.48:

Unhesitating \Unhesitating\
   See hesitating.

WordNet (r) 3.0 (2006):

unhesitating
    adj 1: characterized by quickness and firmness; "his reply was
           unhesitating" [syn: unhesitating, resolute]

Moby Thesaurus II by Grady Ward, 1.0:

92 Moby Thesaurus words for "unhesitating":
   absolute, admitting no exception, all-out, arrogant, assured,
   categorical, clear, cocksure, complete, conclusive, confident,
   convinced, decided, decisive, definite, definitive, determinate,
   determined, downright, entire, explicit, express, final, fixed,
   flat, flat-out, global, hubristic, immediate, implicit,
   inappealable, indisputable, instantaneous, out-and-out, outright,
   overconfident, oversure, overweening, peremptory, perfect,
   persuaded, poised, pompous, positive, prompt, proud, quick, rapid,
   ready, reassured, resolute, round, secure, self-assured,
   self-confident, self-important, self-reliant, staunch, steadfast,
   stick-at-nothing, straight, straight-out, sure, swift, total,
   unafraid, uncircumscribed, unconditional, unconditioned,
   undeviating, undoubting, unequivocal, unfaltering, unflinching,
   unhampered, unhesitant, unlimited, unmistakable, unmitigated,
   unqualified, unquestioning, unreserved, unrestricted, unshrinking,
   unswerving, unwaivable, unwavering, utter, whole, wholehearted,
   without exception, without reserve