fondantPronunciation: /ˈfɒnd(ə)nt/Definition of fondant noun [mass noun] a thick paste made of sugar and water and often flavoured or coloured, used in the making of sweets and the icing and decoration of cakes. [count noun] a sweet made of fondant. Origin: late 19th century: from French, literally 'melting', present participle of fondrefondant in other Oxford dictionaries Definition of fondant in the US English dictionary