Dictionary
qua•si•par•ti•cle
Pronunciation: (kwā"zī-pär'ti-kul, kwā"sī-, kwä"sē, -zē-), [key]—
n. Physics.
an entity, as an exciton or phonon, that interacts with elementary particles, but does not exist as a free particle.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.