Synonyms of key in English:

key


See definition of key

noun

1‘the key to the mystery lay elsewhere’

SYNONYMS
answer, clue, solution, explanation, pointer, cue, lead
basis of, foundation for, requisite for
condition, precondition, essential, means, way, route, path, passport, secret, formula
guide, gloss, glossary, interpretation, explication, translation, clarification, exposition, annotation, index, legend, code

2‘a song in a minor key’

SYNONYMS
tone, pitch, timbre, tonality, tone colour, modulation

3‘it was like the sixties all over again, in a more austerely intellectual key’

SYNONYMS
style, character, mood, vein, spirit, feel, feeling, flavour, quality, humour, atmosphere

adjective

1‘he was a key figure in formulating policy’

SYNONYMS
crucial, central, essential, indispensable, basic, fundamental, pivotal, critical, decisive, dominant, vital, principal, salient, prime, chief, major, leading, main, important, significant
ANTONYMS

secondary, peripheral