指ゆびを鳴ならす

expression, godan verb (-su)

snap one's fingers

The action of making a snapping sound with one's fingers, often to get attention or to a rhythm.

• 彼かれは店てん員いんを呼よぶために指ゆびを鳴ならした。

  He snapped his fingers to call the waiter.

expression, godan verb (-su)

crack one's knuckles; pop one's fingers

Refers to cracking or popping the joints of the fingers, often as a habit or to relieve stiffness.

• 彼かれは考かんがえ事ごとをしながら指ゆびを鳴ならす癖くせがある。

  He has a habit of cracking his knuckles while thinking.