1. A note inserted between the lines or in the margin of a text to explain a difficult or obscure word in the text (this edition of Shakespeare’s works is bolstered by its many glosses on Elizabethan English).
2. A collection of explanations; a glossary (the hornbook’s copious gloss).
3. (usu. pl.) A pronouncement about meaning; an interpretation (the statutory language needs no gloss).
