助手 (zhù shǒu) literally combines 助 (zhù), meaning 'to help' or 'to assist', and 手 (shǒu), meaning 'hand'. Together, they form a noun meaning 'assistant'—someone who lends a hand to support another person’s work. It implies active, practical support rather than just general help, and is commonly used in professional, academic, or organizational settings.

The term carries a neutral-to-formal register and is widely applicable: a teacher’s assistant, a CEO’s executive assistant, or even a lab technician assisting a researcher may all be called 助手. Unlike more casual terms like 帮手 (bāng shǒu), 助手 suggests a defined role with responsibility and some degree of training or qualification. It is not used for temporary or incidental help, nor for animals or objects—despite 手 meaning 'hand', it does not refer to literal hands or animal paws.