Composed of 衣 (yī, "garment / to wear"), one of the oldest Chinese characters — its oracle-bone form depicts a collar and crossed lapels — and 服 (fú, "to wear; clothing"), originally meaning "to comply / submit to," then extended to "garments one puts on." Together they form a common disyllabic noun, as Mandarin generally prefers two-syllable words over single-syllable ones.

Note the pronunciation: the second syllable 服 is toneless (neutral tone) in everyday speech — yī·fu, not yī·fú. This reduction is very common in everyday Mandarin nouns and can trip up learners who over-pronounce every syllable. Also note that 衣服 is a general word; specific items have their own names (裤子 kùzi "pants", 裙子 qúnzi "skirt", etc.).