thumb a lift
To hitchhike. (Done by putting one's thumb in the air in order to signal passing cars that one is looking for a ride.) I spent the summer thumbing lifts along the west coast. We didn't have any money for a taxi, so we had to thumb a life home.
thumb/hitch a ˈlift
stand by the side of the road with your thumb out because you want a driver to stop and take you somewhere: We tried to hitch a lift, but nobody stopped to pick us up.