The head is not more native to the heart, The hand
more instrumental to the mouth. --Shak.
2. (Mus.) Pertaining to, made by, or prepared for, an
instrument, esp. a musical instrument; as, instrumental
music, distinguished from vocal music. ``He defended the
use of instrumental music in public worship.'' --Macaulay.
Sweet voices mix'd with instrumental sounds.
--Dryden.
3. (Gram.) 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.
{Instrumental errors}, those errors in instrumental
measurements, etc., which arise, exclusively from want of
mathematical accuracy in an instrument.