热闹(rè nao) - bustling, lively in Mandarin

热闹 (rènao) describes somewhere full of noise, activity and people - "bustling" or "lively" in the good sense, never "crowded and stressful" the way English sometimes uses "busy". A packed night market or a street full of Chinese New Year stalls is 热闹 (rènao); a motorway traffic jam is not.

热 (rè) on its own means "hot", and 闹 (nào) means "noisy, to make a fuss", but note that in 热闹 (rènao) the second syllable loses its tone in normal speech - it is pronounced with a light, neutral 闹 (nao), not the full falling tone 闹 (nào) it carries elsewhere, for instance in 吵闹 (chǎonào), "noisy, rowdy".

Its natural opposite is 安静 (ānjìng), "quiet". Chinese hospitality often frames a lively gathering as a compliment: 今天真热闹 (jīntiān zhēn rènao), "today was really lively", is the kind of thing a host says happily after a big family meal.