ontario Ontaric • on that · · · Info · Definitions · Characters · · ontario · · Text Latin · · Script 7 · · Length 3 · · Syllables Definitions · · · (noun) the smallest of the Great Lakes. Synonyms: Lake Ontario, Ontario. · · Noun Definition 1 (noun) a prosperous and industrialized province in central Canada. Synonyms: Ontario. · · Noun Definition 2 Characters · · a latin small letter a U+0061 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074