word-forming element used in science and meaning "small, little," from combining form of Latin parvus "small," which is from a metathesized form of PIE *pau-ro-, suffixed form of root *pau- (1) "few, little."

before vowels path-, word-forming element in science and technical terms meaning "suffering, disease," from Greek pathos "suffering, disease" (from PIE root *kwent(h)- "to suffer").

word-forming element used in terms describing kinship of the father or the paternal line, from Latin patri-, combining form of pater (see father (n.)).

before vowels ped-, word-forming element meaning "boy, child," from Greek pedo-, combining form of pais "boy, child," especially a son, from PIE root *pau- (1) "few, little." The British form paed- is better because it avoids confusion with the ped- that means "foot" (from PIE root *ped-) and the ped- that means "soil, ground, earth." Compare, from the same root, Sanskrit putrah "son;" Avestan puthra- "son, child;" Latin puer "child, boy," Oscan puklu "child."

a Brythonic (Celtic) word for "head;" common in place names in Cornwall and Wales (such as Penzance; see also pendragon and Pennsylvania).

word-forming element in words of Greek origin or formation meaning "five, containing five," from Greek penta- (before a vowel pent-), combining form of pente "five," related to Aeolian pempte (from PIE root *penkwe- "five"), with -a- probably by analogy of hepta-, ennea-, deka-.

word-forming element common in words of French and Latin origin, meaning primarily "through," thus also "throughout; thoroughly; entirely, utterly," from Latin preposition per (see per (prep.)).

word-forming element in words of Greek origin or formation meaning "around, about, enclosing," from Greek peri (prep.) "around, about, beyond," cognate with Sanskrit pari "around, about, through," Latin per, from PIE root *per- (1) "forward," hence "in front of, before, first, chief, toward, near, around, against." Equivalent in sense to Latin circum-.

"act of permeating; state of being permeated," 1620s, noun of action from Latin permeare "to pass through" (see permeate).

1898 in the modern sense of "change the order of" (earlier "to change, alter, 16c. but obsolete thereafter), from Latin permutatus, past participle of permutare "change thoroughly, exchange" (see permutation). "Probably regarded by those who use it as a back-formation from permutation" [OED]. Compare permute. Related: Permutated; permutating.