Al'gol, n.

n. [Ar. al ghul, destruction, calamity, fr. ghāla, to take suddenly, destroy, Gr. τῶν ἐν τῷ Γοργονίῳ, ὁ λαμπρός, Ptolem.] (Astron.) A fixed star, in Medusa's head, in the constellation Perseus, remarkable for its periodic variation in brightness.