APA Dictionary of Psychology

n. in some languages, such as Sanskrit, a case of nouns, pronouns, and noun phrases identifying entities that are used by the agent to perform the action of a verb. The instrumental is also used as a category in case grammar; in The crowbar pried open the door, for example, the inanimate noun crowbar is said to be the instrument rather than the agent (here unidentified). See also experiencer; patient.