Gladstone bag vs suitcase

Gladstone bag and suitcase both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gladstone bag	Yes	No	No	No
suitcase	Yes	No	No	No

As nouns, suitcase is a hypernym of Gladstone bag; that is, suitcase is a word with a broader meaning than Gladstone bag:

Other hypernyms of Gladstone bag include bag, grip, traveling bag, travelling bag.

Gladstone bag (noun)	suitcase (noun)
a large travelling bag made of stiff leather	a portable rectangular container for carrying clothes