showcase vs trophy case

showcase and trophy case both are nouns.

Word	Noun	Adjective	Verb	Adverb
showcase	Yes	No	No	No
trophy case	Yes	No	No	No

As nouns, trophy case is a hyponym of showcase; that is, trophy case is a word with a more specific, narrower meaning than showcase:

showcase: a glass container used to store and display items in a shop or museum or home
trophy case: a case in which to display trophies

showcase (noun)	trophy case (noun)
a glass container used to store and display items in a shop or museum or home	a case in which to display trophies
a setting in which something can be displayed to best effect