Main Entry: in·stru·men·tal

Pronunciation: \ˌin(t)-strə-ˈmen-t^əl\

Function: adjective

Date: 14th century

1 a : serving as a crucial means, agent, or tool <was instrumental in organizing the strike> b : of, relating to, or done with an instrument or tool
2 : relating to, composed for, or performed on a musical instrument
3 : of, relating to, or being a grammatical case or form expressing means or agency
4 : of or relating to instrumentalism
5 : operant 3 <instrumental learning> <instrumental conditioning>

— instrumental noun

— in·stru·men·tal·ly \-t^əl-ē\ adverb