street corner vs crossroad

street corner and crossroad both are nouns.

Word	Noun	Adjective	Verb	Adverb
street corner	Yes	No	No	No
crossroad	Yes	No	No	No

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

Other hypernyms of street corner include carrefour, crossing, crossway, intersection.

street corner (noun)	crossroad (noun)
the intersection of two streets	a junction where one street or road crosses another