key

key

adjective

Definition of KEY

1

coming before all others in importance <maintains that Sir Isaac Newton remains the key figure in physical science>

Synonyms arch, big, capital, cardinal, central, chief, dominant, first, grand, great, greatest, highest, key, leading, main, master, number one (also No. 1), numero uno, overbearing, overmastering, overriding, paramount, predominant, preeminent, premier, primal, primary, principal, prior, sovereign (also sovran), supreme

Related Words distinguished, eminent, illustrious, noble, notable, noteworthy, outstanding, prestigious, signal, star, stellar, superior; high-level, senior, top; important, influential, major, mighty, momentous, significant; incomparable, matchless, unequaled (or unequalled), unparalleled, unsurpassed; celebrated, famed, famous, renowned

Near Antonyms inconsequential, inconsiderable, insignificant, minor, negligible, slight, trifling, trivial, unimportant; collateral, inferior, secondary, subordinate, subsidiary

Antonyms last, least

2

of the greatest possible importance <first—and this is key—I wasn't even there that evening>

Synonyms critical, key, pivotal, vital

Related Words decisive, life-and-death (also life-or-death), weighty; basic, elementary, fundamental; essential, indispensable, necessary, requisite; pressing, urgent

Near Antonyms inconsequential, insignificant, minor, trivial, unimportant