Label - definition of label by The Free Dictionary label noun 1. An identifying or descriptive slip: tag, ticket. 2. A name or other device placed on merchandise to signify its ownership or manufacture: brand, colophon, mark, trademark. verb 1. To attach a ticket to: mark, tag, ticket. 2. To set off by or as if by a mark indicating ownership or manufacture: brand, identify, mark, tag, trademark. 3.