hitchhike

from WordNet (r) 3.0 (2006)

hitchhike
    v 1: travel by getting free rides from motorists [syn:
         {hitchhike}, {hitch}, {thumb}]

from The Collaborative International Dictionary of English v.0.48

hitchhike \hitch"hike`\ (h[i^]ch"h[imac]k`), v. i.
   To travel by getting free rides from passing vehicles; as, to
   hitchhike across the country.
   [WordNet 1.5]