anhydridePronunciation: /anˈhʌɪdrʌɪd/Definition of anhydride noun Chemistry the compound obtained by removing the elements of water from a particular acid: sulphur trioxide is the anhydride of sulphuric acid [usually with modifier] an organic compound containing the group C(O)OC(O), derived from a carboxylic acid: maleic anhydrideOrigin: mid 19th century: from Greek anudros (see anhydrous) + -ideanhydride in other Oxford dictionaries Definition of anhydride in the US English dictionary