1) Perfume ingredient 
Ambrein is a triterpene alcohol that is the chief constituent of ambergris, a secretion from the digestive system of the sperm whale, and has been suggested as the possible active component producing the supposed aphrodisiac effects of ambergris. Although ambrein itself is odorless, it serves as the biological precursor for a number of aromatic de...
• (n.) A fragrant substance which is the chief constituent of ambergris.
Am'bre·in noun [ Confer French ambréine . See Amber .] (Chemistry) A fragrant substance which is the chief constituent of ambergris.