Expugn :: Expugn (v. t.) To take by assault; to storm; to overcome; to vanquish; as, to expugn cities; to expugn a person by arguments..
Expugnation :: Expugnation (n.) The act of taking by assault; conquest.
Inexpugnable :: Inexpugnable (a.) Incapable of being subdued by force; impregnable; unconquerable.
Inexpugnably :: Inexpugnably (adv.) So as to be inexpugnable; in an inexpugnable manner.