1. [adj]  under water; e.g. at the bottom of a body of water; "sunken treasure"; "a sunken ship"
2. [adj]  (biology) growing or remaining under water; "viewing subaqueous fauna from a glass-bottomed boat"; "submerged leaves"
3. [adj]  beneath the surface of the water; "submerged rocks"

SUBMERGED is a 9 letter word that starts with S.