fit

\ \ English has three distinct words fit, but the history of them all is very problematical. The verb fit ‘make suitable, be the right size, etc’ [16], and the presumably related adjective ‘proper, appropriate’ [14] may come from a Middle English verb fitten ‘marshal troops’, but that only pushes the difficulty one stage further back, for no one knows where fitten came from. (The derivative outfit dates from the 18th century.) Fit ‘seizure, sudden outburst’ [14] may be the same word as Old English fitt ‘conflict’, whose antecedents again are obscure (fitful was formed from it in around 1600, but was not widely used before the 19th century). Fit ‘section of a poem’ [OE] also comes from an Old English fitt, which might conceivably be identical with Old English fitt ‘conflict’; but an alternative possibility is some connection with Old High German fizza ‘skein’ and Old Norse fit ‘hem’.