the short, thick first digit of the human hand, set lower and apart from the other four and opposable to them

press, move, or touch (something) with one's thumb

as soon as she thumbed the button, the door slid open

turn over (pages) with or as if with one's thumb

I've thumbed my address book and found quite a range of smaller hotels

he was thumbing throughUSA Today for the umpteenth time

request or obtain (a free ride in a passing vehicle) by signalling with one's thumb

three cars passed me and I tried to thumb a lift

he was thumbing his way across France