Definition of inexpugnable in English:

inexpugnable

adjective

archaic
  • Impregnable.

    • ‘I mean the inexpugnable belief that every detailed occurrence can be correlated with its antecedents in a perfectly definite manner exemplifying general principles.’
    • ‘The city is fortified with 150 very strong towers, covered over with ceilings from the upper stories of the buildings in its streets like a crypt, and in a measure inexpugnable.’
    • ‘It evinces an overdiminished but nevertheless inexpugnable desire for moral as well as ethical rectitude.’

Origin

Late Middle English: via Old French from Latin inexpugnabilis, from in- ‘not’ + expugnabilis ‘able to be taken by assault’.

Pronunciation

inexpugnable

/ˌɪnɛkˈspʌɡnəb(ə)l//ˌɪnɪkˈspʌɡnəb(ə)l/