drip mat vs beer mat

drip mat and beer mat both are nouns.

Word	Noun	Adjective	Verb	Adverb
drip mat	Yes	No	No	No
beer mat	Yes	No	No	No

As nouns, beer mat is a hyponym of drip mat; that is, beer mat is a word with a more specific, narrower meaning than drip mat:

drip mat: a small mat placed under a glass to protect a surface from condensation
beer mat: a drip mat placed under a glass of beer

drip mat (noun)	beer mat (noun)
a small mat placed under a glass to protect a surface from condensation	a drip mat placed under a glass of beer