IPA: /ɪnˈɛkspʌɪnəbl/
KK: /ɪnˈɛkspəɡnəbl/
Something that cannot be defeated or conquered, often used to describe a strong position or feeling that cannot be changed.
The fortress was considered inexpugnable due to its high walls and strategic location.
Inexpugnable → It is formed from "in-" (meaning not) and "expugnare" (meaning to conquer or overcome). The word "inexpugnable" means not able to be conquered or overcome.
Think of something that cannot be 'conquered' ('expugnare') — the 'in-' prefix means not, so inexpugnable describes something that is not conquerable.