a. [ Cf. F. instrumental. ] [ 1913 Webster ]

1. Acting as an instrument; serving as a means; contributing to promote; conductive; helpful; serviceable; as, he was instrumental in conducting the business. [ 1913 Webster ]

The head is not more native to the heart,
The hand more instrumental to the mouth. Shak. [ 1913 Webster ]

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. [ 1913 Webster ]

Sweet voices mix'd with instrumental sounds. Dryden. [ 1913 Webster ]

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. [ 1913 Webster ]

Instrumental errors, those errors in instrumental measurements, etc., which arise, exclusively from lack of mathematical accuracy in an instrument. [ 1913 Webster ]

n. (Philos.) The view that the sanction of truth is its utility, or that truth is genuine only in so far as it is a valuable instrument. -- In`stru*men"tal*ist, n.

Instrumentalism views truth as simply the value belonging to certain ideas in so far as these ideas are biological functions of our organisms, and psychological functions whereby we direct our choices and attain our successes. Josiah Royce. [Webster 1913 Suppl.]

n. One who plays upon an instrument of music, as distinguished from a vocalist. [ 1913 Webster ]

n.; pl. Instrumentalities The quality or condition of being instrumental; that which is instrumental; anything used as a means; medium; agency. [ 1913 Webster ]

The instrumentality of faith in justification. Bp. Burnet. [ 1913 Webster ]

The discovery of gunpowder developed the science of attack and defense in a new instrumentality. J. H. Newman. [ 1913 Webster ]

adv. 1. By means of an instrument or agency; as means to an end. South. [ 1913 Webster ]

They will argue that the end being essentially beneficial, the means become instrumentally so. Burke. [ 1913 Webster ]

2. With instruments of music; as, a song instrumentally accompanied. Mason. [ 1913 Webster ]

n. Usefulness or agency, as means to an end; instrumentality. [ R. ] Hammond. [ 1913 Webster ]