PER prep.
e, by itself, of itself. Per is also sometimes used with English words. Per annum, by the year; in each successive year; annually. -- Per cent, Per centum, by the hundred; in the hundred; -- used esp. of proportions of ingredients, rate or amount of interest, and the like; commonly used in the shortened form per cent.…
PER- n.
or, or as an intensive as perhaps, by hap or chance; perennial, that lasts throughout the year; perforce, through or by force; perfoliate, perforate; perspicuous, evident throughout or very evident; perplex, literally, to entangle very much.
PERIOD n. 2 definitions
pletion of a revolution of one of the heavenly bodies; a division of time, as a series of years, months, or days, in which something is completed, and ready to recommence and go on in the same order; as, the period of the sun, or the earth, or a comet.