- mortarboard (n.)
[mortarboard 词源字典]
- also mortar-board, "academic cap," 1854, probably from mortar (1) + board (n.1); so called because it resembles a mason's square board for carrying mortar. Earlier it was called a mortar cap (1680s) or simply morter (c. 1600), from French mortier. [mortarboard etymology, mortarboard origin, 英语词源]