'mortarboard' definitions:

Definition of 'mortarboard'

(from WordNet)
noun
A square board with a handle underneath; used by masons to hold or carry mortar [syn: mortarboard, hawk]
noun
An academic cap with a flat square with a tassel on top

Definition of 'mortarboard'

From: GCIDE
  • mortarboard \mortarboard\, mortar board \mortar board\n.
  • 1. A small square board with a handle beneath, for holding mortar; a hawk; used by masons to hold or carry mortar. [1913 Webster + WordNet 1.5]
  • 2. An academic cap topped by broad, projecting, stiff and flat square top, with a tassel attached to the top and hanging down. It was once worn by students in some colleges, but is now worn usually only at graduation ceremonies. [1913 Webster + WordNet 1.5]