COOH is a chemical formula representing a carboxylic acid group composed of one carbon atom, two oxygen atoms, and one hydrogen atom. When it comes to synonyms, carboxyl and carboxylic group are often used interchangeably with COOH. Other alternative terms for COOH include carboxylate, carboxylic acid functional group, and CO2H. Additionally, you may often find COOH referred to as a '-COOH' group. Despite the multiple synonyms, the meaning of the chemical formula remains the same and holds substantial importance within organic chemistry as it forms the basic building block for amino acids and fatty acids.