Pronunciation: (brō'mēn, -min),[key] —n.Chem. an element that is a dark-reddish, fuming, toxic liquid and a member of the halogen family: obtained from natural brines and ocean water, and used chiefly in the manufacture of gasoline antiknock compounds, pharmaceuticals, and dyes. Symbol: Br; at. wt.: 79.909; at. no.: 35; sp. gr.: 3.119 at 20°C.