Definition of troll

• (Scandanavian folklore) a supernatural creature (either a dwarf or a giant) that is supposed to live in caves or in the mountains
• a partsong in which voices follow each other; one voice starts and others join in one after another until all are singing different parts of the song at the same time; "they enjoyed singing rounds"
• a fishermans lure that is used in trolling; "he used a spinner as his troll"