"in each year, annually," c. 1600, Latin, "by the year," from per (see per) + annum, accusative singular of annus "year" (see annual (adj.)).

1510s, "by the day, in each day," Latin, "by the day," from per (see per) + diem, accusative singular of dies "day" (from PIE root *dyeu- "to shine"). As a noun from 1809, "amount or allowance of so much every day."

1680s, Latin, "by the head, by heads," from per (see per) + capita "head" (see capital).

1680s, Latin, "by families, by stocks;" in legal use, for inheritances, etc., opposed to per capita. See per- + stirpes.

[A]pplied to succession when divided so as to give the representatives belonging to one branch the share only that their head or ancestor would have taken had he survived. Thus, in a gift to A and the children of B, if they are to take per capita, each child will have a share equal to that of A; but if they are to take per stirpes, A will take one half and the other half will be divided among the children of B. [Century Dictionary]

French, from Latin per excellentiam "by the way of excellence." French par "by, through, by way of, by means of" is from Latin per (see per). For second element, see excellence.

1797, contraction of and per se and, meaning "(the character) '&' by itself is 'and' " (a hybrid phrase, partly in Latin, partly in English). An earlier form of it was colloquial ampassy (1706). The distinction is to avoid confusion with & in such formations as &c., a once common way of writing etc. (the et in et cetera is Latin for "and"). The letters a, I, and o also formerly (15c.-16c.) were written a per se, etc., especially when standing alone as words.

The symbol is based on the Latin word et "and," and comes from an old Roman system of shorthand signs (ligatures) attested in Pompeiian graffiti, and not (as sometimes stated) from the Tironian Notes, which was a different form of shorthand, probably invented by Cicero's companion Marcus Tullius Tiro, which used a different symbol, something like a reversed capital gamma, to indicate et. This Tironian symbol was maintained by some medieval scribes, including Anglo-Saxon chroniclers, who sprinkled their works with a symbol like a numeral 7 to indicate the word and.

In old schoolbooks the ampersand was printed at the end of the alphabet and thus by 1880s the word ampersand had acquired a slang sense of "posterior, rear end, hindquarters."

"passed, done, or effected through the skin," 1862, with -ous  + Latin per cutem "through the skin," from per "through" (see per) + cutem, accusative singular of cutis "skin" (from PIE root *(s)keu- "to cover, conceal"). Related: Percutaneously.

"by, for," mid-13c., from Old French par, per, from Latin per (see per). It figures in some French phrases borrowed into English and in the formation of some words (parboil, pardon, parvenu). In some older borrowings from French it has been re-Latinized to per- (perceive, perfect, perform, pertain).