isotonic
adjective /ˌaɪsəʊˈtɒnɪk/
/ˌaɪsəʊˈtɑːnɪk/
- (of a drink) with added minerals and salts, intended to replace those lost during exerciseWord Originearly 19th cent. (as a musical term designating a system of tuning, characterized by equal intervals): from Greek isotonos, from isos ‘equal’ + tonos ‘tone’.