Something inorganic is not made of living stuff, and did not come from plants, animals, or other living things. In science class this is the big split: organic chemistry looks at the carbon compounds life is built from; inorganic chemistry looks at the rest — rocks, metals, salts, water, many gases. A stone is inorganic; a leaf is not. Though actually, chemists are both tidier and messier than that sentence. In the lab, “organic” mainly means “contains carbon,” even if nobody grew it, and a few carbon things still get called inorganic. Outside the lab, people also say inorganic fertilizer for the chemical kind you buy in a bag, as against compost and manure. Writers sometimes stretch it further, to mean “not grown naturally” — a team or a style that was put together, not born. Shoppers talking about food usually say “not organic,” not “inorganic”; “inorganic apples” would sound odd. The word can also name the stuff itself: inorganics, meaning inorganic materials.