WordNet (r) 3.0 (2006):

turn tail
    v 1: flee; take to one's heels; cut and run; "If you see this
         man, run!"; "The burglars escaped before the police showed
         up" [syn: scat, run, scarper, turn tail, lam,
         run away, hightail it, bunk, head for the hills,
         take to the woods, escape, fly the coop, break
         away]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "turn tail":
   abscond, absquatulate, beat a retreat, bolt, clear out, come about,
   cut and run, decamp, depart, desert, elope, fetch about, flee, fly,
   fugitate, go AWOL, go about, heel, jump, jump bail, levant,
   make off, pivot, pivot about, put about, round, run, run away,
   run away from, run away with, run for it, run off, show the heels,
   skedaddle, skip, skip out, slip the cable, spin, swing,
   swing round, swivel, take French leave, take flight,
   take to flight, take wing, turn, turn about, turn around,
   turn round, veer, veer around, wheel, wheel about, whirl