WordReference Random House Unabridged Dictionary of American English © 2025
tro•po•nin
(trō′pə nin, trop′ə-),USA pronunciation n. [Biochem.]
- Biochemistrya protein of muscle tissue that binds calcium ions and is involved in contraction.
- tropo(myosin) (see tropo-, myosin) + -n- (of uncertain origin, originally) + -in2 1965–70