(n) a genetic disease (autosomal recessive) in which an enzyme needed to metabolize galactose is deficient or absent; typically develops shortly after birth
n. (Chem.) A white, crystalline sugar, C6H12O6, isomeric with dextrose, obtained by the decomposition of milk sugar, and also from certain gums. When oxidized it forms mucic acid. Called also lactose (though it is not lactose proper). [ 1913 Webster ]