(Μήστρα), a daughter of Erysichthon, and granddaughter of Triopas (whence she is called Triopcis, Ov. Met. 8.872). She was sold by her hungry father, that he might obtain the means of satisfying his hunger. In order to escape from slavery, she prayed to Poseidon, who loved her, and conferred on her the power of metamorphosing herself whenever she was sold, and of thus each time returning to her father. (Tzetz. ad Lyc. 1393; Ov. Met. 8.847, &c.; Ant. Lib. 17, who calls her Hypermestra.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890