“Fit to be tied” is a sort of puzzling thing to say. Is it supposed to mean you’re “fit” as in able (“all fit to go”), as in “physically fit,” as in “appropriate” (“a fit subject for discussion”), carefully measured (“fitted suit”), or something else? And what’s all this about being tied? Does it mean bound up with a rope, having the same score in a game, or wearing a skinny ascot to accompany your sport jacket?
Taken as a whole, “fit to be tied” means very angry. So angry, in fact, that either you ought to be tied down for your own safety. Or maybe your anger itself is inducing a sort of paralysis where you can’t decide what to do. The phrase was in use in the early 1800s, but was considered slang. You can tell it was slang because when it was printed in the Champion and Sunday Review in 1819, it was placed in quotes: “It is amusing to mark the rage and disappointment of the Courier. … ‘It is absolutely fit to be tied.’”
The meaning of “fit” used in “fit to be tied” is the one where you’re inclined or ready for something. There have been quite a few other “fit to be…” phrases that have come and gone ever since the 1500s. In 1587 there was “When men are heauie [heavy] laden with griefe and sorowe, then are they fittest to call for…”. In the 1700s you could find “fit to sink”, “fit to kill”, “fit to hang,” “fit to freeze,” and in the 1800s the best of the bunch showed up: “Fit to choke a dozen MacBeths.”
“Fit” itself has been around since Old English, when there might have been two very similar words. There was the “fit” (“fytte”) that meant a section of something, either a song, a poem, or a piece of cloth that was a section of something bigger, like a drapery. Then there was also the “fit” (“fitte”) that meant a conflict or struggle. This one is still around in the sense of “having a fit” like a tantrum. The first might be connected to the way we use “fit” to mean your shoes are the right size.
But neither of those original “fits” seem particularly connected to the various other meanings of “fit” that have arisen since. “Fit” was first used as a verb in Morte Arthur around 1400, but it meant assembling your soldiers for battle. What might have happened to “fit” after that is the general sense of preparing was generalized and applied to things like “fitting for a journey,” which is now “outfitting.” Once that was normalized, the next evolution of “fit” could have been the more figurative “having become prepared for something,” and that’s where the adjective form in “fit to be…” came from.
But of course this is all speculation, and fit for the recycle bin, where it will fit easily and nobody will pitch a fit!
