Periodic — Defs

01 a. Pertaining to, derived from, or designating, the highest oxygen acid (HIO4) of iodine.

1.
Pertaining to, derived from, or designating, the highest oxygen acid (HIO4) of iodine.(Chem.)

02 a. Of or pertaining to a period or periods, or to division by periods.

1.
Of or pertaining to a period or periods, or to division by periods.
“The periodical times of all the satellites.” — Sir J. Herschel.
2.
Performed in a period, or regular revolution; proceeding in a series of successive circuits; as, the periodical motion of the planets round the sun.
3.
Happening, by revolution, at a stated time; returning regularly, after a certain period of time.
“The periodic return of a plant's flowering.” — Henslow.

“To influence opinion through the periodical press.” — Courthope.
4.
Acting, happening, or appearing, at fixed or somewhat variable intervals; recurring; as, periodical epidemics
5.
Of or pertaining to a period; constituting a complete sentence.(Rhet.)