Title text:
'This HAZMAT container contains radioactive material with activity of one becquerel.' 'So, like, a single banana slice?'
Transcript:
[Cueball holds a stick while talking with Megan and White Hat.]
Cueball: This stick is one meter long.
Megan: Cool.
White Hat: That's a nice stick.[Cueball holds a smallish rock.]
Cueball: This rock weighs one pound.
Megan: I'd believe it.
White Hat: Looks like a normal rock.[Cueball holds a small battery.]
Cueball: This battery is one volt.
Megan: Seems fine.
White Hat: Might need a recharge.[Cueball holds a capacitor while Megan and White Hat panic.]
Cueball: This capacitor is one farad.
Megan: Aaaaa! Be careful!!
White Hat: Put it down!!
Source: https://xkcd.com/3106/
That's similar to saying "Auf Wiedersehen" translated to English is "until I see you again", therefore "Auf Wiedersehen" is technically English. Just because there's a recognised translation to a thing, that doesn't make it that thing.
It's not a recognised translation- it's the definition.
If we're going to split hairs then while it's defined in terms of metric units, it doesn't scale with prefixes and factors of 10, so it can't be an S.I. unit.
You're right, the imperial units are not S.I. units, but each (most?) imperial unit is defined by an S.I. unit.
The other way around maybe, that is, an English word becoming technically foreign because we decide that we are going to write its definition in a different language in the dictionary.
It wouldn't make sense to do that though, which kind of breaks the analogy. Unless you count words borrowed wholesale because we didn't have that word, and those definitions were written in a foreign language first.
As it is "one pound" now translates exactly to "nought point four five three five nine two three seven kilograms" where it didn't before 1959. "kilogram" is one of those foreign borrowings.