Gratis in English is a colloquialism adopted from the various Romance and Germanic languages, ultimately descending from the plural ablative and dative form of the first-declension noun grātia in Latin. It means “free of charge”, “at zero price”, “free”, in the sense that some good or service is supplied without payment, even though it may have value.
Libre in English is adopted from the various Romance languages, ultimately descending from the Latin word lībere; its origin is closely related to liberty. It denotes “the state of being free”, as in “liberty” or “having freedom”. The Oxford English Dictionary (OED) considers libre to be obsolete, but the word has come back into limited use. Unlike gratis, libre appears in few English dictionaries, although there is no other English single-word adjective signifying “liberty” exclusively, without also meaning “at no monetary cost”.
by The Punjapit Alliance