mortarboard

English Thesaurus

1. an academic cap with a flat square with a tassel on top (noun.artifact)

hypernym	:	cap,
definition	:	a tight-fitting headdress (noun.artifact)

part meronym	:	academic costume,
definition	:	a costume worn on formal occasions by the faculty or students of a university or college (noun.artifact)

2. a square board with a handle underneath; used by masons to hold or carry mortar (noun.artifact)

hypernym	:	board,
definition	:	a flat piece of material designed for a special purpose (noun.artifact)