adj. 25B6; adjective MOST IMPORTANT, of greatest importance, of greatest significance, uppermost, top, first (and foremost), highest, pre-eminent, predominant, principal, primary, paramount, chief, main, major, foremost, central, key, focal, pivotal; informal number-one.
OVERRIDING
Meaning of OVERRIDING in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012