bastion fort vs fortress

bastion fort and fortress both are nouns.

Word	Noun	Adjective	Verb	Adverb
bastion fort	Yes	No	No	No
fortress	Yes	No	No	No

As nouns, fortress is a hypernym of bastion fort; that is, fortress is a word with a broader meaning than bastion fort:

bastion fort: a fortification composed of many projecting triangular bastions (usually from five to eight), specifically designed to cover each other; first seen in the mid-15th century in Italy.
fortress: a fortified defensive structure

Other hypernyms of bastion fort include fort.

bastion fort (noun)	fortress (noun)
a fortification composed of many projecting triangular bastions (usually from five to eight), specifically designed to cover each other; first seen in the mid-15th century in Italy.	a fortified defensive structure