您贵姓(nín guì xìng) - what is your name? (polite, lit. "your honourable surname") in Mandarin

您贵姓 (nín guì xìng) is the polite way to ask someone's surname. It uses 您 (nín), the respectful form of "you", and 贵 (guì), which normally means "expensive" but here works as an honorific meaning roughly "your esteemed", the same courtesy prefix seen in 贵国 (guì guó, "your honourable country").

It is deliberately more formal than 你叫什么 (nǐ jiào shén me, "what is your name"), and the honest answer format matches: reply with just the surname, 我姓王 (wǒ xìng wáng, "my surname is Wang"), rather than a full name. Using 您贵姓 (nín guì xìng) on a close friend would sound oddly stiff - it belongs in shops, offices, and first introductions with someone older or senior.

An English speaker's instinct is to translate 贵 (guì) literally as "expensive" and get confused, but the honorific sense here has nothing to do with price.