Brackish – (adjective) 1. Somewhat salty or briny water. Used to refer to the area where a fresh-water river mixes with a salt-water inlet. Saltier than a river, but not as salty as the ocean. 2. Distasteful or unpleasant. Etymology: First recorded in 1550–60; from Dutch brak “salty” + -ish Synonyms: briny, saltine, salted, salty …