‘Gē zhi’ is a colloquial verb meaning ‘to tickle’—specifically, to lightly touch or stroke someone’s sensitive body areas (like the ribs, armpits, or neck) to provoke laughter or squirming. Though written with two characters, 胳 and 肢, neither stands alone with this meaning: ‘gē’ here is a phonetic component borrowed from ‘gē bo’ (arm), and ‘zhī’ means ‘limb’—together they form an onomatopoeic, reduplicated-sounding compound that evokes the light, repetitive motion of tickling.

This word is informal and commonly used in playful, familial, or child-oriented contexts—between parents and young children, siblings, or close friends. It rarely appears in formal writing or serious speech. Note that it’s almost always used as a transitive verb requiring an object (e.g., ‘gē zhi tā’ — ‘tickle him/her’), and the action implies gentle, non-harmful physical play.