A sweet white (or brownish yellow) crystalline substance, of a sandy or granular consistency, obtained by crystallizing the evaporated juice of certain plants, as the sugar cane, sorghum, beet root, sugar maple, etc. It is used for seasoning and preserving many kinds of food and drink. Ordinary sugar is essentially sucrose. See the Note below.
By extension, anything resembling sugar in taste or appearance; as, sugar of lead (lead acetate), a poisonous white crystalline substance having a sweet taste.