The semantic role of the entity (usually inanimate) that the agent uses to perform an action or start a process WordNet 3.0 & Open English WordNet

In grammar, the instrumental case is a grammatical case used to indicate that a noun is the instrument or means by or with which the subject achieves or accomplishes an action. Wikipedia

A grammatical case Wikipedia Disambiguation

Grammatical case Wikidata

A mechanical device intended to perform a task. OmegaWiki

A means or agency for achieving an effect. Wiktionary

A noun case used to express means or agency—and is generally indicated in English by by or with with the objective. Languages that use the instrumental case include Armenian, Serbo-Croatian, Czech, Dyirbal, Georgian, Latvian, Slovene, Polish, Quechua, Russian, Assamese, Turkish and Sanskrit. Extinct languages that used the instrumental case include Old English, Old Saxon and Old High German. Wiktionary

Case to express agency or means. Wiktionary (translation)