twiddle one’s thumbs

twiddle (one's) thumbs

To wait idly because one cannot take action or has nothing to do at the moment. Although the phrase refers to an actual movement of the hand (in which one's fingers are interlaced and each thumb is brought over the other in succession), the phrase is usually used figuratively. I'm just twiddling my thumbs here in the ER, waiting for someone to give me an update on Claire's condition.
See also: thumb, twiddle

twiddle one’s thumbs

tv. to do nothing; to wait nervously, playing with one’s fingers. I sat twiddling my thumbs while you were out doing I don’t know what all!
See also: thumb, twiddle