1. In animals, a cell or group of cells that secretes a specific substance. Endocrine glands secrete directly into the bloodstream, while exocrine glands secrete through ducts into a cavity or to the surface of the body.
2. An anatomical structure that resembles a gland, especially a lymph node (not in technical usage ).
3. In plants, a cell or group of cells that secrete substances, e.g. a nectary gland.