collins vs Tom Collins

collins and Tom Collins both are nouns.

Word	Noun	Adjective	Verb	Adverb
collins	Yes	No	No	No
Tom Collins	Yes	No	No	No

As nouns, collins and Tom Collins are synonyms defined as:

collins and Tom Collins: tall iced drink of liquor (usually gin) with fruit juice

collins (noun)	Tom Collins (noun)
tall iced drink of liquor (usually gin) with fruit juice	tall iced drink of liquor (usually gin) with fruit juice