The Collaborative International Dictionary of English v.0.48:

Push \Push\, v. t. [imp. & p. p. Pushed; p. pr. & vb. n.
   Pushing.] [OE. possen, pussen, F. pousser, fr. L. pulsare,
   v. intens. fr. pellere, pulsum, to beat, knock, push. See
   Pulse a beating, and cf. Pursy.]
   1. To press against with force; to drive or impel by
      pressure; to endeavor to drive by steady pressure, without
      striking; -- opposed to draw.
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            Sidelong had pushed a mountain from his seat.
                                                  --Milton.
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   2. To thrust the points of the horns against; to gore.
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            If the ox shall push a manservant or maidservant, .
            . . the ox shall be stoned.           --Ex. xxi. 32.
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   3. To press or urge forward; to drive; to push an objection
      too far. " To push his fortune." --Dryden.
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            Ambition pushes the soul to such actions as are apt
            to procure honor to the actor.        --Spectator.
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            We are pushed for an answer.          --Swift.
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   4. To bear hard upon; to perplex; to embarrass.
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   5. To importune; to press with solicitation; to tease.
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   To push down, to overthrow by pushing or impulse.
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The Collaborative International Dictionary of English v.0.48:

Pushing \Push"ing\, a.
   Pressing forward in business; enterprising; driving;
   energetic; also, forward; officious, intrusive. --
   Push"ing*ly, adv.
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WordNet (r) 3.0 (2006):

pushing
    n 1: the act of applying force in order to move something away;
         "he gave the door a hard push"; "the pushing is good
         exercise" [syn: push, pushing]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "pushing":
   adventuresome, adventurous, aggressive, ambitious, assertive,
   brash, busy, busybody, driving, dynamic, enterprising, forceful,
   forward, go-ahead, hustling, impertinent, inquisitive, meddlesome,
   meddling, militant, motive, nosy, officious, overweening,
   presuming, presumptuous, propellant, propelling, propulsive,
   propulsory, prying, pulsive, pushful, pushy, self-appointed,
   self-asserting, self-assertive, shoving, snoopy, up-and-coming,
   uppish, uppity, venturesome, venturous