A troll was a mythical being with supernatural powers found in the mythology of various cultures, including Earth. Its name could also have insulting connotations.
In 2366, Lwaxana Troi called DaiMon Tog "a toad-faced troll" during the Trade Agreements Conference after his repeated advances towards her and an offer to purchase her. (TNG: "Ménage à Troi")
In 2369, Q called Quark a "disgusting little troll" after making him disappear when he attempted to meet Vash in her quarters. (DS9: "Q-Less")
Later that year Lwaxana, believing Quark had stolen her latinum hair brooch, called him a "little troll". (DS9: "The Forsaken")
In 2370, Kira Nerys referred to the Ferengi as trolls during a discussion with Jadzia Dax. (DS9: "Rules of Acquisition")
That same year, Tumak described Nog as a "big-eared troll". (DS9: "Sanctuary")
Not long after, Kira referred to Quark as "the little troll who runs the dabo tables" when speaking to Vedek Bareil Antos. (DS9: "Shadowplay")
In 2375, Intendant Kira Nerys called Quark and Rom "two little trolls". (DS9: "The Emperor's New Cloak")