Synonyms for Key:

adj.

central (adjective)
nuclear, pivotal.
essential, important (adjective)
main, fundamental, leading, pivotal, principal, major, chief, crucial, primary.
focal (adjective)
central, core, essential, focal, asymptotic, nuclear, convergent.
important (adjective)
serious, crucial, meaningful.

n.

B, chord, crotchet, D, DO, C, bass, beat, double flat. back, blurb, book, appendix, body, artwork, chief, principal, paramount, premier, major, addendum, main, afterword, top, first, number one, leading, prime, primary, binding, foremost, capital, acknowledgments. feature, element, essence, priority, burning issue/question, pivotal, basis, concern, staple. character set, control, CAPS LOCK, command key, route, delete key, arrow key, Alt key, secret, control key, means, backspace, formula, CTRL. drag, hover, input, double-click, click, drag-and-drop, enter. damper, bridge, catgut, fret, head, drumstick, bellows, bow, hammer. checklist, blue book, calendar, glossary, hot list, chronicle, bibliography, blacklist, hit list. key ring, combination, fob, master key, Pass-key, latchkey, bunch, code, skeleton key. answer, solution (noun)
marker, core, cue, pointer, ticket, means, brand, code, sign.
essential (noun)
chief, pivotal, principal.
indication (noun)
cue, marker, designation, icon, prompt, semaphore, lighthouse, token, guidepost, symbol, alert, badge, gesture, ticket, sign, insignia, signpost, logotype, logo, signal, motion, indication, emblem, flag, banner, beacon, hint, legend, label, figuration, brand, wink, notation, wave, crest, stamp, tag, pointer, gesticulation, denotation.
island (noun)
atoll, reef, islet, Holm, archipelago, island, isle, cay.
item that unlocks (noun)
latchkey.
key (noun)
describe, Francis Scott Key, cay, primal, key out, identify, operative, tonality, fundamental, kg, Florida Keys, winder, distinguish, cardinal, significant, central, name, kilogram, discover, of import, kilo, important.
key signature (noun)
tonality.
person (noun)
Francis Scott Key.

v.

cognition (verb)
describe, distinguish, discover, identify, name, key out.

Other synonyms:

damper, basis, drag-and-drop, catgut, premier, double-click, hover, latchkey, Pass-key, master key, skeleton key, principal, key ring. bellows, control, paramount, code, fret, priority, primary, pivotal, leading, drumstick, foremost, backspace, essence, main. element, fob, staple, major. click, first, formula, input, bow, prime, combination. route, concern. secret, drag. bunch, bridge. hammer. head. francis scott key
Francis Scott Key.

Usage examples for key

  1. " It'll stop a key from the outside. – The Quality of Mercy by W. D. Howells
  2. Here is the key of the gate. – Love of Brothers by Katharine Tynan
  3. Well, wouldn't he give you the key – The Port of Adventure by Charles Norris Williamson and Alice Muriel Williamson