Bilingual means speaking two languages like a native. A bilingual child, bilingual signs, fully bilingual.
Most of the world is bilingual or more, and the monolingual countries are the unusual ones. A bilingual child often mixes both languages early and sorts them out later, which alarms parents needlessly. Bilingual signs show both languages together.
1adjectivebilingualSpeaking two languages like a native.
“Their children are bilingual, speaking English at school and Italian at home.”
bilingual is a quality.
Latin bilinguis means two-tongued — bi, two, plus lingua, a tongue or language.
Latin
bilinguis
English, today
bilingual
From Latin bilinguis al; equivalent to bi- + lingual.
Etymology from Wiktionary, CC BY-SA