rummer vs drinking glass

rummer and drinking glass both are nouns.

Word	Noun	Adjective	Verb	Adverb
rummer	Yes	No	No	No
drinking glass	Yes	No	No	No

As nouns, drinking glass is a hypernym of rummer; that is, drinking glass is a word with a broader meaning than rummer:

rummer: a large drinking glass (ovoid bowl on a stem) for drinking toasts
drinking glass: a container made of glass for holding liquids while drinking

Other hypernyms of rummer include glass.

rummer (noun)	drinking glass (noun)
a large drinking glass (ovoid bowl on a stem) for drinking toasts	a container made of glass for holding liquids while drinking