Interesting !

Though I've always been a bit confused between tailbone and classic length as I thought it depended on where the tailbone (or is it tail bone?) ended ?
But to confuse things even more I sometimes read butt length in American/ English, presumably butt meaning the buttocks ? Whilst in - what does one call it ? – English/ English ?

we say bottom length....

In fact I wasn’t all that surprised when I saw quite a heavy, thick Dictionary recently giving English and American spellings and meanings for the same word ! Boot for trunk, bumper for fender, bonnet for hood....

It must be really funny yet terribly confusing for a while for say newly weds who whilst desperately anxious not to give offence to their precious one and only, are completely unfamiliar with it all when they first start to live in each other's country !
"Where did you put my suitcases dear ?"
"In your trunk darling."
Or....
“Could you move the bumper closer to the fire dearest “?
Or….
“Sweetheart, could you lift up my bonnet please ?”
There must be dozens more as these are the only ones I can remember !