Why was "tantrum" trending last week?
c.1300, probably from or related to Old Norse flengja "to flog," of uncertain origin. The Middle English intransitive sense is that suggested by phrase have a fling at "make a try." An obsolete word for "streetwalker, harlot" was fling-stink (1670s). Related: Flung; flinging.
"attempt, attack," early 14c.; see fling (v.). Sense of "period of indulgence on the eve of responsibilities" first attested 1827. Meaning "vigorous dance" (associated with the Scottish Highlands) is from 1806.