from
The Collaborative International Dictionary of English v.0.48
Instrumental \In`stru*men"tal\, a. [Cf. F. instrumental.]
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1. Acting as an instrument; serving as a means; contributing
to promote; conductive; helpful; serviceable; as, he was
instrumental in conducting the business.
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The head is not more native to the heart,
The hand more instrumental to the mouth. --Shak.
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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.
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Sweet voices mix'd with instrumental sounds.
--Dryden.
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3. (Gram.) Applied to a case expressing means or agency; as,
the instrumental case. This is found in Sanskrit and
Russian 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.
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{Instrumental errors}, those errors in instrumental
measurements, etc., which arise, exclusively from lack of
mathematical accuracy in an instrument.
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