gaol vs bastille

gaol and bastille both are nouns.

Word	Noun	Adjective	Verb	Adverb
gaol	Yes	No	Yes	No
bastille	Yes	No	No	No

As nouns, bastille is a hyponym of gaol; that is, bastille is a word with a more specific, narrower meaning than gaol:

gaol: a correctional institution used to detain persons who are in the lawful custody of the government (either accused persons awaiting trial or convicted persons serving a sentence)
bastille: a jail or prison (especially one that is run in a tyrannical manner)

Other hyponyms of gaol include holding cell, hoosegow, hoosgow, house of correction, lockup, workhouse.

gaol (noun)	bastille (noun)
a correctional institution used to detain persons who are in the lawful custody of the government (either accused persons awaiting trial or convicted persons serving a sentence)	a jail or prison (especially one that is run in a tyrannical manner)

gaol (verb)	bastille (verb)
lock up or confine, in or as in a jail