What does "per" mean?

Per: Through; by means of; through the agency of; by; for; for each; as, per annum; per capita, by heads, or according to individuals; per curiam, by the court; per se, 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 diem, by the day. [For other phrases from the Latin, see Quotations, Phrases, etc., from Foreign Languages, in the Supplement.]