A docent is a person who walks visitors through a museum, a church, or an old house and explains what they are looking at. In American English this is the usual word; the person may be a volunteer, not a paid professor. In British English people more often say guide. It is a formal, slightly specialist word. You put it on a badge, not in a text to a friend. Though actually, in some Central European universities docent is also a teaching rank, a kind of lecturer — same Latin root “to teach,” different job. For this entry, the museum-and-church sense is the one that matters.

導覽員（博物館、教堂等；台灣也說解說員。歐陸有些大學的 docent 則是教職，不是這個意思）