1. Either of a pair of glands found in the nasal region of most marine birds and many reptiles that remove excess salt (sodium chloride) from the blood and excrete it via the nostrils. Typically it consists of numerous lobes surrounding a central canal; each lobe contains many secretory tubules arranged radially around a duct, which drains into the canal. Blood capillaries run alongside the tubules in a countercurrent arrangement, and salt is actively pumped across the tubule wall from the blood into the lumen of the salt gland, using a mechanism similar to that of the rectal gland of elasmobranch fishes. However, the resulting solution has an osmolarity greater than that of the blood.

2. A gland found in certain plants, especially ‘salt-loving’ plants (halophytes) or desert plants, that excretes accumulated sodium chloride onto the leaves.