“A source of confusion is that ‘citron’ in French and English are false friends, as the French word ‘citron’ refers to what in English is a lemon; whereas the French word for the citron is ‘cédrat’.
…
Other languages that use variants of citron to refer to the lemon include Armenian, Czech, Dutch, Finnish, German, Estonian, Latvian, Lithuanian, Hungarian, Esperanto, Polish and the Scandinavian languages.[citation needed]”
https://en.wikipedia.org/wiki/Citron
For the lazy:
“A source of confusion is that ‘citron’ in French and English are false friends, as the French word ‘citron’ refers to what in English is a lemon; whereas the French word for the citron is ‘cédrat’.
…
Other languages that use variants of citron to refer to the lemon include Armenian, Czech, Dutch, Finnish, German, Estonian, Latvian, Lithuanian, Hungarian, Esperanto, Polish and the Scandinavian languages.[citation needed]”