飞机 (fēi jī) literally means 'flying machine' — 飞 (fēi) means 'to fly', and 机 (jī) means 'machine' or 'device'. Together, they form the standard, neutral term for 'airplane' or 'aeroplane' in modern Mandarin. It refers specifically to powered, fixed-wing aircraft designed for air travel and is used in everyday speech, news, transportation contexts, and official documents.

The word is unmarked for formality and works equally well in casual conversation ('I’m taking a plane tomorrow') and formal settings ('The flight was delayed'). Unlike some English synonyms (e.g., 'jet' or 'aircraft'), 飞机 doesn’t imply size, speed, or military use — it’s the default, all-purpose noun for civilian and commercial airplanes. It’s rarely used metaphorically and almost never in compound words without modification (e.g., you wouldn’t say *飞机车*; instead, use *飞机票* for 'airplane ticket').