unconquerable

adjective

not capable of being conquered

Wiktionary

Pronunciation: /ʌnˈkɒŋkəɹəbəl/

adj

Etymology: Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Germanic *un- Proto-West Germanic *un- Old English un- Middle English un- English un- English conquerable English unconquerable From un- + conquerable.

Not conquerable; indomitable.
“Be careful when power comes to thee also, lest thou too shouldst smite in thine anger or thy jealousy, for unconquerable strength is a sore weapon in the hands of erring man.”
“In computing, the unconquerable trilemma is embodied in the well-known CAP theorem for distributed systems, also called Brewer’s CAP theorem. This states that any distributed database can only attain two of three guarantees: consistency, availability and partition tolerance.”

noun

Someone or something that cannot be conquered.