to combine with oxygen, or subject to the action of oxygen, or of an oxidizing agent.-to combine with oxygen or with more oxygen; to add oxygen to; as, to oxidize nitrous acid so as to form nitric acid.-to remove hydrogen from (anything), as by the action of oxygen; as, to oxidize alcohol so as to form aldehyde.-to subject to the action of oxygen or of an oxidizing agent, so as to bring to a higher grade, as an -ous compound to an -ic compound; as, to oxidize mercurous chloride to mercuric chloride.