Blackfriar vs friar

Blackfriar and friar both are nouns.

Word	Noun	Adjective	Verb	Adverb
Blackfriar	Yes	No	No	No
friar	Yes	No	No	No

As nouns, friar is a hypernym of Blackfriar; that is, friar is a word with a broader meaning than Blackfriar:

Blackfriar: a Roman Catholic friar wearing the black mantle of the Dominican order
friar: a male member of a religious order that originally relied solely on alms

Other hypernyms of Blackfriar include mendicant.

Blackfriar (noun)	friar (noun)
a Roman Catholic friar wearing the black mantle of the Dominican order	a male member of a religious order that originally relied solely on alms