key (object designed to open and close a lock) / spanner, wrench / key / clef / keystone / flight (unit) / V formation (V-shaped flight formation) / radical (element of a logogram)

second-person singular imperative of kluczyć

(idiomatic) monkey wrench

monkey wrench

keyword (word used as a key to a code) / keyword (reserved word used to identify a specific command, function etc.)

(idiomatic) plumber wrench, Swedish wrench

(cryptography) public key

(idiomatic, music) treble clef

(cryptography) private key

(idiomatic, music) treble clef