'左手' literally means 'left hand' — a compound noun formed by combining 左 (zuǒ), meaning 'left', and 手 (shǒu), meaning 'hand'. It refers specifically to the hand on the left side of the human body, opposite the right hand. In Chinese, direction words like 左 and 右 frequently combine with body-part nouns to form precise anatomical terms.

This term appears in everyday contexts such as giving directions ('Turn left with your left hand facing forward'), describing physical conditions ('My left hand is numb'), or in traditional practices like martial arts or acupuncture, where left- and right-side distinctions matter for technique or diagnosis. Unlike English, Chinese does not use articles, so 左手 stands alone without 'the' or 'a'; context determines definiteness.