1690s, from French glande (Old French glandre, 13c.), from Latin glandula "gland of the throat, tonsil," diminutive of glans (genitive glandis) "acorn, nut; acorn-shaped ball," from PIE root *gwele- "acorn" (cf. Greek balanos, Armenian kalin, Old Church Slavonic zelodi "acorn;" Lithuanian gile "oak"). Earlier English form was glandula (c.1400).
A cell, a group of cells, or an organ that produces a secretion for use in or for elimination from the body.
Any of various organs, such as lymph nodes, that resemble true glands but perform a nonsecretory function.
An organ or group of specialized cells in the body that produces and secretes a specific substance, such as a hormone. See also endocrine gland, exocrine gland.