From Latin 'bilinguis' (two-tongued) — its Latin ancestor was often derogatory, meaning 'deceitful,' a connotation the modern word has shed.
Speaking two languages fluently; expressed in or using two languages.
From Latin 'bilinguis,' meaning 'speaking two languages,' composed of 'bi-' (two, from earlier 'dui-') and 'lingua' (tongue, language). The Latin 'bi-' descends from the PIE root *dwóh₁ (two), while 'lingua' (earlier 'dingua') comes from PIE *dn̥ǵʰwéh₂s (tongue, language). In Classical Latin, 'bilinguis' often carried a pejorative connotation of 'double-tongued' or 'deceitful,' reflecting Roman suspicion of people who moved between languages and cultures. Key roots: bi- (from *dwóh₁) (Latin / PIE: "two"), lingua (from *dn̥ǵʰwéh₂s) (Latin / PIE: "tongue
In Classical Latin, 'bilinguis' was often an insult meaning 'double-tongued' or 'deceitful' — Virgil used it to describe treacherous Carthaginians — reflecting the Roman view that someone who spoke two languages was inherently untrustworthy, a prejudice that has been thoroughly debunked by modern neuroscience.