instrumental
adj.adj. being a very important part of making something happen. You use this when someone or something helps a plan succeed.
adj. serving as a crucial means, agent, or tool in bringing about a specific result. Often used to describe a person's role in a successful project or negotiation.
She was instrumental in winning the contract for our team.
The local community was instrumental in raising the funds needed to repair the historic library.
While many factors contributed to the treaty's success, her diplomatic skill proved instrumental in bridging the gap between the two opposing factions during the final hours of negotiation.
From Middle English instrumental, instrumentale, from Medieval Latin īnstrūmentālis, equivalent to instrument + -al.
Commonly followed by the preposition 'in' and a gerund or noun phrase.
He was instrumental for the success.He was instrumental in the success.When describing a role in an outcome, the adjective typically takes the preposition 'in' rather than 'for'.