mortarboard

[mawr-ter-bawrd, -bohrd]

noun

a board, usually square, used by masons to hold mortar.
Also called cap. a cap with a close-fitting crown surmounted by a stiff, flat, square piece from which a tassel hangs, worn as part of academic costume.

Origin of mortarboard

First recorded in 1850–55; mortar² + board

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for mortarboard

Contemporary Examples of mortarboard

Backstage earlier, McCaskill had given me tips on how to bobby pin the mortarboard cap to my head.
A College Degree Worth the Wait
Eleanor Clift
June 1, 2014

Historical Examples of mortarboard

As for the mortarboard and gown, undergraduate opinion rather requires that they be left behind.
An American at Oxford
John Corbin
Mr. Worthington pushed back his mortarboard and revealed the crimson chevron which it had bitten into his bald brow.
Rest Harrow
Maurice Hewlett
A right instinct sent him tiptoe over his lawn, another made him doff his mortarboard.
Rest Harrow
Maurice Hewlett

British Dictionary definitions for mortarboard

mortarboard

noun

a black tasselled academic cap with a flat square top covered with cloth
Also called: hawk a small square board with a handle on the underside for carrying mortar

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for mortarboard

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.