The definition of influential is someone or something that has an impact on or shapes how people act or how things occur.
Having a share in bringing about a result
Having a beneficial use; serviceable:
Producing a strong impression or response; striking:
The definition of essential is completely necessary or part of the basic nature of something.
(Music) Of, relating to, or performed by singing:
Find another word for instrumental. In this page you can discover 26 synonyms, antonyms, idiomatic expressions, and related words for instrumental, like: crucial, assisting, influential, contributory, partly responsible for, conducive, useful, of service, effective, helpful and necessary.