adj. Pertaining to, derived from, or designating, the highest oxygen acid (HIO�) of iodine.adj. Of or pertaining to a period or periods, or to division by periods.adj. Performed in a period, or regular revolution; proceeding in a series of successive circuits.adj. Happening, by revolution, at a stated time; returning regularly, after a certain period of time; acting, happening, or appearing, at fixed intervals; recurring.adj. Of or pertaining to a period; constituting a complete sentence.