Scholium \Scho"li*um\, n.; pl. L. {Scholia}, E. {Scholiums}. [NL., fr. Gr. ?, fr. ?. See {School}.] 1. A marginal annotation; an explanatory remark or comment; specifically, an explanatory comment on the text of a classic author by an early grammarian. 2. A remark or observation subjoined to a demonstration or a train of reasoning.