adj.
Pronunciation: ˌ in(t)-str ə - ' men-t ə l
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 ə l- ē \ adverb