impregnable

UK:

/ɪmpɹˈɛɡnəbə‍l/ US:

/ˌɪmˈpɹɛɡnəbəɫ/

lýsingarorð

óvinnandi (impregnable camp, fortress)
ósigrandi

Samheiti: conceptive, inexpugnable, inviolable, secure, strong, unassailable, unattackable