套
tào · HSK 2
to cover
🧥 套 tào = cover/sheath; a measuring word for sets like a suit of clothes
套 originally meant a cover or case that wraps something. From there it became the measure word for things that come as a matched set — a suit, a set of furniture, a series of books.
套 — big 大 + long 镸 (long hair)
套 combines 大 (big) over 镸 (long), suggesting something large and elongated that wraps or covers. The original sense was a covering or sheath that fits over something else, later extending to 'set,' 'cover,' or 'to slip over.' Modern uses like 一套 (a set) and 手套 (gloves) preserve this idea of an enclosing wrapper.