What is the meaning of Shaka?

A greeting gesture in which the thumb and little finger are extended while curling the three middle fingers in a semi-fist, used to express a variety of positive meanings including all right, hello and goodbye.

joke, prank

third-person singular past historic of shaker

Rōmaji transcription of しゃか

joke (thing said to amuse)

want

look for, seek

shark

doubt

worry

error

Source: wiktionary.org