Back eccentric

the eccentric that reverses or backs the valve gear and the engine.

See also: Eccentric

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
When the screen went back eccentric Andre burst into the song It Had To Be You - to the delight of 21-year-old drama student Moriamo and thunderous cheers from the audience.