Abiogenic refers to something that is not formed by or resulting from living organisms. The opposite, or antonym, of abiogenic is biogenic, which means formed or caused by living organisms. Biogenic materials include organic matter such as plants, animals, and microorganisms, as well as substances that are derived from them, such as fossil fuels. Another antonym for abiogenic is organic, which is used to describe things that are derived from living organisms, such as food, textiles, and medicines. Abiogenic and biogenic are two important concepts in fields such as geology, chemistry, and biology.