serving as a means; helpful (in bringing something about)
of or performed with an instrument or tool
of, performed on, or written for a musical instrument or instruments
of or in keeping with instrumentalism
Gram. designating, of, or in the case of nouns, pronouns, or adjectives expressing means or agency
noun
a composition for a musical instrument or instruments
Gram.
the instrumental case: this case is expressed by inflection in Old English, Sanskrit, Russian, etc., and in English with the prepositions by or with (Ex.: OE ðȳ spere, “by the spear, with the spear”)