Definition of: serial comma

A comma placed before an and which joins the last two in a series of three or more substantives, adjectives, phrasal modifiers, or adverbs. ♦ Opinion is evenly divided as to whether the serial comma is needed. The best argument for its use, which is observed in this dictionary, is that it makes the meaning unmistakable and the relation between the various modifiers unmistakably clear: The motion was opposed by Lords Arundel, Salisbury, Somerset, and Say and Sele. If the last comma (the serial comma) were omitted here, there could be confusion as to the name of the last peer, which is Say and Sele.