The English have long had a liking for playing with words, often mutilating foreign words for fun. I remember a British veteran of WWI telling me that the soldiers had taken to pronouncing Ypres as “wipers”.
There are also stories of Rotten Row, the name of an avenue in Hyde Park, being a bastardization of Route du roi, and of Elephant and Castle, a street and neighbourhood south of the Thames, coming from Enfant de Castile. And these stories are so charming and entertaining that it would be a shame to have to say toodle-oo to them.
Ah, yes, toodle-oo. That’s another one said to come from French, specifically from à toute à l’heure. But it has a problem shared with Rotten Row and Elephant and Castle: a complete lack of any evidence, beyond similarity of sound, of a French source. And etymology by sound is not sound etymology, as linguists will tell you – it’s exceedingly easy to find sound coincidences with seemingly plausible related meanings. (Meanwhile, Ypres has not been renamed Wipers, but there is no reason to think the British soldiers did not say it as “wipers”; I got that from the horse’s mouth.)
Of course, if there were a single clear origin it would be easier to lay to rest forever the French origin theories. But one simply doesn’t always get a nice, easily traceable source. So, yes, your honour, it is possible that the accused had, without anyone knowing, become an expert marksman, and that he drove 500 miles in three hours without anyone noticing, let alone stopping him, and that he managed to get his wheelchair up three flights of stairs. After all, the victim was shot with a weapon of the same type as the accused had been seen looking at in a store two weeks ago, and was known to have bullied the accused in elementary school. And it is possible that these terms come from French.
But there are other possible origins that may be a bit less of a stretch. For instance, Elephant and Castle comes from an inn sign taken from the coat of arms of the Worshipful Company of Cutlers, which featured an elephant with a castle on its back. And there are several streets called Rotten Row in towns throughout England, and there are various more likely possibilities for its origin – route du roi has not been entirely discounted, but it is not convincing.
As to toodle-oo, we know that it showed up in the early 20th century, no later than 1907 – not a time when French influences were prone to appearing spontaneously in English discourse. Aside from the supposed French origin, which is discounted by researched etymological sources, there are two main ideas about its origins. One sees it as coming from tootle, which is a variant of toddle, as in toddle off – it means to walk with a tottering or waddling step, like a young child, or, more loosely, to amble; toddle off just means “go” with a somewhat leisurely tone to it. The other sees it as coming from toot, in imitation of a car horn; its occasional co-occurrence with pip-pip, which is also imitative of a car horn, supports this. (The merger of the two, tootle-pip, was invented much later, in the 1970s.)
If it sounds, at any rate, like the sort of thing P.G. Wodehouse’s Bertie Wooster might have used, well, he was indeed an early user of it. The earliest use so far found comes from a 1907 issue of Punch magazine, which, as The Phrase Finder points out, employed P.G. Wodehouse at the time. Another early user was T.E. Lawrence (as in Lawrence of Arabia), who in 1908 wrote in a letter “Tootle ’oo.” It would seem it was a bit au courant with the smart set of the time. It remains in usage, as we know, but with a general taste of reference to the effete toffs of the legendary Wodehousian era. Toodle-oo has since then also been abbreviated to toodles, which is even more popular, if not quite as much a reference to another social milieu.
It’s a fun word, regardless. The oo and oo seem like the embouchure of a person making the /u/ sound, or perhaps the end of a flute on which one is playing something that sounds rather similar. The /dl/ in the middle adds to the musicality – it does show up in filler syllables in various traditions, from the lodle-lodle-lodle-lo of some shape note music to yodeling, and it seems imitative of twiddling keys – and has a certain frilly ornamentation to it, with the tongue cupping to the roof of the mouth and then pulling away from the sides, perhaps giving a reminiscence of the fringes on the canopy of an old horseless carriage in some form of frippery. You know, the sort of old car that had a bulb horn that might even go “toodle-oo” as the car and driver toddled off.
Thanks to C. Fletcher for suggesting toodle-oo.