翅膜 (chì mó) is a technical noun used primarily in entomology to refer to the thin, transparent, membranous tissue that forms the main surface of an insect’s wing — such as those of dragonflies, bees, or wasps. The character 翅 means 'wing', while 膜 means 'membrane' or 'thin flexible layer', so the compound literally means 'wing membrane'. It emphasizes structural composition rather than function or motion.

This term appears mainly in scientific descriptions, biology textbooks, and nature documentaries about insects. It is not used in everyday conversation and rarely occurs outside academic or educational contexts. Unlike general terms like 翅膀 (chìbǎng, 'wing'), which refers to the whole organ, 翅膜 specifically denotes the delicate, veined, translucent part essential for flight mechanics and aerodynamic efficiency.