litreyoudaoicibaDictYouDict[litre 词源字典]
litre: [19] Litre goes back to Greek lītrā, a term which denoted a Sicilian monetary unit. This found its way via medieval Latin litrā into French as litron, where it was used for a unit of capacity. By the 18th century it had rather fallen out of use, but in 1793 it was revived, in the form litre, as the name for the basic unit of capacity in the new metric system.

It is first recorded in English in 1810. The Greek word was descended from an earlier, unrecorded *līthrā, which was borrowed into Latin as lībra ‘pound’. This is the source of various modern terms for units of weight, and hence of currency, including Italian lira and the now disused French livre, and it also lies behind the English symbol £ for ‘pound’.
=> level, lira[litre etymology, litre origin, 英语词源]