adj. 25B6; adjective STEADFAST, resolute, staunch, firm, decided, determined, unswerving, unwavering; unyielding, inflexible, dogged, obstinate, persistent, indefatigable, tireless, unflagging, unremitting, unrelenting, relentless.
UNSHAKEABLE
Meaning of UNSHAKEABLE in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012