Wiktionary
malonic acid
n. (context organic compound English) a white crystalline dicarboxylic acid, CH2(COOH)2, used in making barbiturates
Wikipedia
Malonic acid
Malonic acid ( IUPAC systematic name: propanedioic acid) is a dicarboxylic acid with structure CH(COOH). The ionized form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's diethyl ester. The name originates from the Greek word μᾶλον (malon) meaning 'apple'.