WordNet (r) 3.0 (2006):

pushy
    adj 1: marked by aggressive ambition and energy and initiative;
           "an aggressive young executive"; "a pushful insurance
           agent" [syn: pushful, pushy]

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "pushy":
   adventuresome, adventurous, aggressive, ambitious, arrogant,
   assertive, audacious, bold, brash, brassy, brazen, bumptious, busy,
   busybody, cheeky, cocky, cold, controlled, contumelious, cool,
   disdainful, driving, dynamic, enterprising, familiar, firm-minded,
   forceful, forward, go-ahead, hubristic, hustling, impertinent,
   importunate, independent, inquisitive, insolent, insulting, loud,
   meddlesome, meddling, militant, nosy, obnoxious, obtrusive,
   offensive, officious, overpresumptuous, overweening, presuming,
   presumptuous, procacious, prying, pushful, pushing, self-appointed,
   self-asserting, self-assertive, self-controlled, self-expressive,
   self-possessed, self-restrained, showy, snoopy, strong-minded,
   strong-willed, up-and-coming, uppish, uppity, venturesome,
   venturous