commonplace vs hackneyed

commonplace is a noun but hackneyed is not a noun.

Word	Noun	Adjective	Verb	Adverb
commonplace	Yes	Yes	No	No
hackneyed	No	Yes	No	No

As adjectives, commonplace and hackneyed are synonyms defined as:

commonplace and hackneyed: repeated too often; overfamiliar through overuse

Other synonyms of commonplace include banal, old-hat, shopworn, stock, threadbare, timeworn, tired, trite, well-worn.

commonplace (noun)	hackneyed (noun)
a trite or obvious remark

commonplace (adjective)	hackneyed (adjective)
not challenging; dull and lacking excitement	repeated too often; overfamiliar through overuse
repeated too often; overfamiliar through overuse
completely ordinary and unremarkable