Old English treowian "to trust, believe," from treow "faith, belief," from Proto-Germanic *truwian (see true). Cognate with German trauen.
in early Scandinavian folklore, giant, monstrous being, sometimes possessing magic powers. Hostile to men, trolls lived in castles and haunted the surrounding districts after dark. If exposed to sunlight they burst or turned to stone. In later tales trolls often are man-sized or smaller beings similar to dwarfs and elves. They live in mountains, sometimes steal human maidens, and can transform themselves and prophesy. In the Shetland and Orkney islands, Celtic areas once settled by Scandinavians, trolls are called trows and appear as small malign creatures who dwell in mounds or near the sea. In the plays of the Norwegian dramatist Henrik Ibsen, especially Peer Gynt (1867) and The Master Builder (1892), trolls are used as symbols of destructive instincts. Trolls in modern tales for children often live under bridges, menacing travelers and exacting tasks or tolls.