Source : Webster's Revised Unabridged Dictionary (1913)

Keyed \Keyed\ (k[=e]d), a.
   Furnished with keys; as, a keyed instrument; also, set to a
   key, as a tune.

   {Keyed bugle}. See {Kent bugle}.

Source : WordNet®

keyed
     adj 1: so adjusted as to be appropriate or brought into harmony;
            "an industry not attuned to the demands of the
            market"; "a remark keyed to the situation"; "charges
            finely tuned to the amount a student can afford" [syn:
             {attuned}, {tuned}]
     2: fitted with or secured by a key; "a keyed instrument"; "the
        locks have not yet been keyed" [ant: {keyless}]
     3: set to a key or tone