noun
employer's house; employer; place of apprenticeship
Historical term for the household or master where one served as a live-in apprentice or domestic servant, common in the Edo period. The word can refer to the physical house, the employer, or the apprenticeship itself.
江戸時代、若者は奉公先で読み書きや礼儀を学んだ。
In the Edo period, young people learned reading, writing, and manners at their place of apprenticeship.
彼は十歳で奉公先へ出された。
He was sent out to his employer's house at the age of ten.
奉公人 is the person who serves, whereas 奉公先 is the destination or employer of that service.
Compound of 奉公 (service, apprenticeship) and 先 (destination, place). The exact historical derivation is uncertain, but the word reflects the Edo-period practice of live-in service.