gamin vs street urchin

gamin and street urchin both are nouns.

Word	Noun	Adjective	Verb	Adverb
gamin	Yes	No	No	No
street urchin	Yes	No	No	No

As nouns, street urchin is a hypernym of gamin; that is, street urchin is a word with a broader meaning than gamin:

gamin: (sometimes offensive) a homeless boy who has been abandoned and roams the streets
street urchin: a child who spends most of his time in the streets especially in slum areas

Other hypernyms of gamin include guttersnipe.

gamin (noun)	street urchin (noun)
(sometimes offensive) a homeless boy who has been abandoned and roams the streets	a child who spends most of his time in the streets especially in slum areas