n.
Function: transitive verb
Date: 14th century
1 : to lock with or as if with a key : FASTEN : as a : to secure (as a pulley on a shaft) by a key b : to finish off (an arch) by inserting a keystone
2 : to regulate the musical pitch of
3 : to bring into harmony or conformity : make appropriate : ATTUNE <remarks key ed to a situation>
4 : to identify (a biological specimen) by a key
5 : to provide with identifying or explanatory cross-references <instructions key ed to accompanying drawings ― John Gartner>
6 : to make nervous, tense, or excited ― usually used with up <was key ed up over her impending operation>
7 : KEYBOARD ― often used with in
8 : to be essential to : play the most important part in <defense key ed the victory>
intransitive verb
1 : to use a key
2 : to observe the position or movement of an opposing player in football in order to anticipate the play ― usually used with on
3 : KEYBOARD