1. square academic caps with flat tops and tassels, worn at graduation ceremonies
2. square boards with handles underneath, used by masons for holding mortar
Usage: construction

Examples

• The graduates threw their mortarboards into the air after the ceremony.
• She adjusted the tassel on her mortarboard before walking across the stage.
• The construction worker carried fresh mortar on his mortarboard.
• Black mortarboards dotted the sky as the class of 2024 celebrated.
• The mason used several mortarboards to keep different types of mortar separated.
• Her mortarboard kept slipping during the long graduation speech.