Mortarboards are a type of headwear traditionally worn by university graduates during their graduation ceremonies. They consist of a flat board, usually made of cardboard or plastic, with a tassel attached to the center. The term 'MORTARBOARD' comes from the resemblance of the hat to the tool used by masons to hold mortar. The four-letter word CAPS is an acronym for 'cap and gown, ' which is another name for the MORTARBOARD.