The Collaborative International Dictionary of English v.0.48:

getaway \get"a*way`\ n.
   rapid acceleration. [WordNet sense 1]

   Syn: pickup.
        [WordNet 1.5]

   2. a rapid escape (as by criminals); as, the thieves made a
      clean getaway; they made their getaway in a stolen car.
      [WordNet sense 2]

   Syn: lam.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

getaway
    n 1: the attribute of being capable of rapid acceleration; "his
         car has a lot of pickup" [syn: pickup, getaway]
    2: a rapid escape (as by criminals); "the thieves made a clean
       getaway"; "after the expose he had to take it on the lam"
       [syn: getaway, lam]

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "getaway":
   abandonment, acceleration, break, breakout, decampment,
   deliverance, delivery, departure, drive, egress, emergence, escape,
   escapism, evacuation, evasion, exit, exodus, extrication, flight,
   freeing, going, hegira, impetus, issuance, issue, jailbreak, lam,
   leak, leakage, leaving, liberation, outlet, parting, passing,
   pickup, prisonbreak, quickening, release, removal, rescue,
   retirement, retreat, riddance, scape, setting-free, slip, speedup,
   step-up, thrust, vent, walkout, withdrawal