'买卖' (mǎi mài) is a compound noun meaning 'business' or 'trade' — literally 'buying and selling'. Though composed of two verbs (买 'to buy' and 卖 'to sell'), it functions exclusively as a noun in modern Mandarin and never as a verb. It emphasizes commercial activity as a whole, especially small-scale or informal transactions, such as street vendors, market stalls, or family-run shops.

The word often carries a neutral-to-slightly colloquial tone and appears in contexts like describing the state of commerce ('生意不好，买卖难做' — 'Business is slow; trade is hard to do'), referring to a specific transaction ('这桩买卖很划算' — 'This deal is very worthwhile'), or naming types of commerce ('粮食买卖' — 'grain trade'). Unlike '生意' (shēngyì), which is broader and more common in formal or abstract contexts, '买卖' feels more concrete and action-oriented, frequently highlighting the exchange process itself.