prime mover 
noun
1A person who is chiefly responsible for the creation or execution of a plan: he was a prime mover in the construction of the railway...
- She was a prime mover in the creation of her sport's ruling body, the Women's Tennis Association, and the creation of a professional tour in 1970.
- It would build social trust, since young mothers brought together through children's centres are prime movers in local communities.
- ‘It exists to encourage freedom of expression and promote free thought,’ says Shravan Narula, a third year engineering student, who is the prime mover of the project.
2An initial source of motive power: a manufacturer of prime movers...
- The vehicles and equipment included in this initial purchase include six prime movers, six fuel tanker trailers and four dolly converters.
- They were able also to install powerful prime movers (water wheels or steam-engines) to drive all their machines.
- Stowed within this hold are two bulldozers with scrapers attached, several flatbed trucks, a diesel-powered roller, a prime mover, two tractors and some truck trailers.
- interbreed
- intercalary
- intercalate
- intercalation
- intercede
- interceder
- intercellular
- intercensal
- intercept
- interception
- interceptive
- interceptor
- intercession
- intercessional
- intercessor
- intercessory
- interchain
- interchange
- interchangeability
- interchangeable
- interchangeableness
- interchangeably
- intercity
- inter-class
- intercollegiate