Citron
A source of confusion is that "citron" or similar words in French (and other languages), and English are false friends, as they refer to the lemon. Indeed, into the 16th century, the English name "citron" included the lemon and perhaps the lime as well.
Lime (fruit)
Note that the tree species known in Britain as lime trees ("Tilia" sp.), called "linden" in other dialects of English, are broadleaf temperate plants unrelated to the citrus fruits.