ThaliaPronunciation: /ˈθeɪlɪə, θəˈlʌɪə, ˈtɑːlɪə/Definition of Thalia 1 Greek & Roman Mythology the Muse of comedy. 2 Greek Mythology one of the Graces. Origin:Greek, literally 'rich, plentiful'Thalia in other Oxford dictionaries Definition of Thalia in the US English dictionary