(a.) Acting as an instrument; serving as a means;
contributing to promote; conductive; helpful; serviceable; as, he was
instrumental in conducting the business.
(a.) Pertaining to, made by, or prepared for, an
instrument, esp. a musical instrument; as, instrumental music,
distinguished from vocal music.
(a.) Applied to a case expressing means or agency; as, the
instrumental case. This is found in Sanskrit as a separate case, but in
Greek it was merged into the dative, and in Latin into the ablative. In
Old English it was a separate case, but has disappeared, leaving only a
few anomalous forms.
