Yes, thumbs is a Scrabble word!

Verb

1. Travel by getting free rides from motorists

2. Look through a book or other written material

3. Feel or handle with the fingers

Noun

1. The thick short innermost digit of the forelimb

2. The part of a glove that provides a covering for the thumb

3. A convex molding having a cross section in the form of a quarter of a circle or of an ellipse