Oxford Dictionary
unshakeable
unshakeable |ʌnˈʃeɪkəb (ə )l |(also unshakable ) ▶adjective (of a belief, feeling, or opinion ) strongly felt and unable to be changed: my unshakeable faith in the goodness of mankind. • unable to be disputed or questioned: an unshakeable alibi. DERIVATIVES unshakeability |-ˈbɪlɪti |noun, unshakeably adverb
Oxford Thesaurus
unshakeable
unshakeable adjective they both have an unshakeable confidence in the rightness of their own opinions: steadfast, resolute, staunch, firm, constant, decided, determined, fixed, ingrained, unswerving, unwavering, unvacillating, unfaltering, unflinching; unyielding, inflexible, dogged, obstinate, persistent, unassailable, immovable, irremovable, indelible, iron, adamant, deep-dyed, indefatigable, tireless, unflagging, unremitting, unrelenting, relentless. ANTONYMS weak, half-hearted.
Sanseido Wisdom Dictionary
unshakeable
ù n sh á ke a ble -sh á k -形容詞 〖通例 名詞 の前で 〗確固たる, 揺るぎない 〈信念など 〉; 不動の .