gypsy cab vs taxicab

gypsy cab and taxicab both are nouns.

Word	Noun	Adjective	Verb	Adverb
gypsy cab	Yes	No	No	No
taxicab	Yes	No	No	No

As nouns, taxicab is a hypernym of gypsy cab; that is, taxicab is a word with a broader meaning than gypsy cab:

gypsy cab: a taxicab that cruises for customers although it is licensed only to respond to calls
taxicab: a car driven by a person whose job is to take passengers where they want to go in exchange for money

Other hypernyms of gypsy cab include cab, hack, taxi.

gypsy cab (noun)	taxicab (noun)
a taxicab that cruises for customers although it is licensed only to respond to calls	a car driven by a person whose job is to take passengers where they want to go in exchange for money