This article or section is in need of attention from an expert on the subject. WikiProject Chemistry or the Chemistry Portal may be able to help recruit one. If a more appropriate WikiProject or portal exists, please adjust this template accordingly. (November 2008)
nor- is a chemical acronym and prefix. It comes from the Germannitrogen ohne Rest, "no residues at nitrogen." Residues are groups such as a methyl-group that are part of a larger molecule. Despite the word "nitrogen", it is also used in reference to other "stripped-down" molecules. For example, a norbornyl group (bicyclo[2.2.1]heptane) is a bornyl group (1,7,7-trimethylbicyclo[2.2.1]heptane) lacking the three different methyls at carbons.
Examples of chemicals with a nor- prefix include noradrenaline.