A chemical formed from benzene rings, originally call "aromatic" because of benzene's distinctive aroma. Solvents, many types of pesticides, and polychlorinated biphenyls are composed of aromatic hydrocarbons.
An organic compound that contains a benzene ring within its structure or that has chemical properties similar to benzene
An aromatic hydrocarbon (abbreviated as AH) or arene Definition IUPAC Gold Book http://www.iupac.org/goldbook/A00435.pdf Link is a hydrocarbon, the molecular structure of which incorporates one or more planar sets of six carbon atoms that are connected by delocalised electrons numbering the same as if they consisted of alternating single and double covalent bonds. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent. The configuration of six carbon atoms in aromatic compounds is known as a benzene ring, after the simplest possible aromatic hydrocarbon, benzene.