Ĭn'stru-mĕnt'al, a.
a. [Fr., Pr., Sp., & Pg. instrumental, It. instrumentale, istrumentale, strumentale.]
Sense 1. Acting as an instrument; serving as a means; contributing to promote; conducive; helpful; serviceable.
The head is not more native to the heart, The hand more instrumental to the mouth. Shak.
Sense 2. Pertaining to, made by, or prepared for, musical instruments; as, instrumental music, distinguished from vocal music.
He defended the use of instrumental music in public, on the ground that the notes of the organ had a power to counteract the influence of devils. Macaulay.