fantasiaPronunciation: /fanˈteɪzɪə, ˌfantəˈziːə/Definition of fantasia noun a musical composition with a free form and often an improvisatory style. a musical composition based on several familiar tunes. a thing composed of a mixture of different forms or styles:the theatre is a kind of Moorish and Egyptian fantasiaOrigin: early 18th century: from Italian, 'fantasy', from Latin phantasia (see fantasy)fantasia in other Oxford dictionaries Definition of fantasia in the US English dictionary