\Bai"ly's beads\ (Astron.) A row of bright spots observed in connection with total eclipses of the sun. Just before and after a total eclipse, the slender, unobscured crescent of the sun's disk appears momentarily like a row of bright spots resembling a string of beads. The phenomenon (first fully described by Francis Baily, 1774 -- 1844) is thought to be an effect of irradiation, and of inequalities of the moon's edge.