mortarboard

1. is a type of: board - a flat piece of material designed for a special purpose
   same as: hawk
2. is a type of: cap - a tight-fitting headdress
   is a part of: academic costume - a costume worn on formal occasions by the faculty or students of a university or college

Other Searches

• Rhyme: Dillfrog, RhymeZone
• Definition: Wiktionary, Dictionary.com, Wikipedia, Merriam-Webster, WordNet, Power Thesaurus
• Imagery: Google, Flickr, Bing