Meaning of INSTRUMENTAL in English

INSTRUMENTAL

I. in ‧ stru ‧ men ‧ tal 1 /ˌɪnstrəˈmentl◂, ˌɪnstrʊˈmentl◂/ BrE AmE adjective

1 . be instrumental in (doing) something formal to be important in making something happen:

He was instrumental in developing links with European organizations.

2 . instrumental music is for instruments, not for voices

—instrumentally adverb

II. instrumental 2 BrE AmE noun [countable]

a piece of music in which no voices are used, only instruments

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.