The Collaborative International Dictionary
Key \Key\, v. t. [imp. & p. p. Keved; p. pr. & vb. n. Keying.]
To fasten or secure firmly; to fasten or tighten with keys or wedges.
(Computers) To enter (text, data) using keys, especially those on a keyboard; to keyboard; as, to key the data in by hand.
To adjust so as to be maximally effective in a particular situation; -- of actions, plans, or speech; as, to key one's campaign speech to each local audience.
To furnish with a key or keys. To key up.
(Arch.) To raise (the whole ring of an arch) off its centering, by driving in the keystone forcibly.
(Mus.) To raise the pitch of.
Hence, (fig.), to produce nervous tension in; as, the whole team was keyed up for the championship game.