number two; No. 2; second designated item
Used as a numbered label or designation. In everyday modern writing, Arabic-numeral 2号 is very common for this literal sense.
Old-fashioned and often disparaging euphemism for a kept mistress or concubine, implying a woman treated as 'No. 2' after the wife. Avoid as a neutral modern term.
Typhoon No. 2 is approaching Okinawa.
Car No. 2 will stop toward the front of the platform.
A rumor spread that he had a mistress.
In the old novel, she appears as a powerful man's concubine.
There are rumors that she has become the company president's mistress.
That man apparently keeps a young woman as his mistress.
愛人 is the common modern word for a lover or mistress, whereas 二号 is an old-fashioned, often derogatory euphemism implying she is treated as 'No. 2' after the wife.
妾 is an older, more formal term for a kept concubine, while 二号 is a colloquial, somewhat derisive way of saying the same thing.
mistress; kept woman
Standard kanji spelling; used for both the literal numbering sense and the older figurative sense.
Common practical spelling for numbered labels such as models, vehicles, rooms, typhoons, and routes; not normally used for the mistress sense.
Written with 二 'two' and 号 'number; designation', literally 'number two.' The mistress sense is a figurative euphemistic extension from the idea of a secondary partner; the exact historical development is not specified.