job, business for to do for someone / arrest

(historical) researchers who were employed by Tokugawa shogunate and studied Japanese and/or Japan-related history (Japanology).

What? What did you say?

Nothing

what / that thing (used in place of words you can't remember at the moment.)

孫の手: backscratcher

犬小屋: doghouse

五つ子: quintuplets

万劫: an extremely long period of time; eternity

内語: native language; internal language