Meaning of synchronous rotation

syn'chronous rota'tion

Pronunciation: [key]
— Astron. Astron.
  1. rotation of a satellite in which the period of rotation is equal to the period of orbit around its primary, leaving the same face always pointing toward the primary: The moon is in synchronous rotation about the earth.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.