WordNet (r) 3.0 (2006):

hightail
    v 1: leave as fast as possible; "We hightailed it when we saw
         the police walking in"

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "hightail":
   begone, bound, canter, clear out, cut and run, cut out, decamp,
   flee, fly, fox-trot, gallop, get, git, hop, hop along, hotfoot,
   kite, leap, lope, make tracks, run, run along, run away,
   run away from, run off, scram, skedaddle, spring, sprint, step,
   step along, step lively, take off, take to flight, trip, trot,
   vamoose