clipboard vs writing board

clipboard and writing board both are nouns.

Word	Noun	Adjective	Verb	Adverb
clipboard	Yes	No	No	No
writing board	Yes	No	No	No

As nouns, writing board is a hypernym of clipboard; that is, writing board is a word with a broader meaning than clipboard:

clipboard: a small writing board with a clip at the top for holding papers
writing board: work surface consisting of a wide lightweight board that can be placed across the lap and used for writing

clipboard (noun)	writing board (noun)
a small writing board with a clip at the top for holding papers	work surface consisting of a wide lightweight board that can be placed across the lap and used for writing