winder, discover, describe, tonality, identify, cardinal, significant, KG, fundamental, important, more...

irrelevant, trivial, unimportant, peripheral, insignificant

house key, car key, mailbox key, padlock key, skeleton key, door key, garage key, keycard, more...

primary, public, private, low, same, minor, secret, foreign, major, delete, important

cycle starter,   important part,   keyboard keys,   important point,   typewriter part,   important factor,   vital role,   leads to success,   essential respects,   it fits in a lock