1 [mass noun] a sweet crystalline substance obtained from various plants, especially sugar cane and sugar beet, consisting essentially of sucrose, and used as a sweetener in food and drink:a spoonful of sugar [as modifier]:a sugar bowl
[count noun] a lump or teaspoonful of sugar, used to sweeten tea or coffee:I’ll have mine black with two sugars
2 Biochemistry any of the class of soluble, crystalline, typically sweet-tasting carbohydrates found in living tissues and exemplified by glucose and sucrose.
3 informal, chiefly North American used as a term of endearment:what’s wrong, sugar?
4 [as exclamation] informal used as a euphemism for ‘shit’:‘Oh sugar!’ cried Sally
5 informal a narcotic drug, especially heroin or LSD:bags full of extra-fine Colombian sugar
1sweeten, sprinkle, or coat with sugar:Mother absent-mindedly sugared her tea (as adjective sugared)sugared almonds
[no object] (usually as noun sugaring) Entomology spread a mixture of sugar, treacle, beer, etc., on a tree trunk in order to catch moths.
2make more agreeable or palatable:the novel was preachy but sugared heavily with jokes