Five
Old English fīf, of Germanic origin; related to Dutch vijf and German fünf, from an Indo-European root shared by Latin quinque and Greek pente .
wiktionary
From Middle English five, vif, fif, from Old English fīf(“five”), from Proto-West Germanic *fimf(“five”), from Proto-Germanic *fimf(“five”) (compare West Frisian fiif, Dutch vijf, German fünf, Norwegian and Swedish fem, Icelandic fimm), from Proto-Indo-European *pénkʷe (compare Welsh pump, Latin quinque, Tocharian A päñ, Tocharian B piś, Lithuanian penki, Russian пять(pjatʹ), Albanian pesë, pêsë, Ancient Greek πέντε(pénte), Armenian հինգ(hing), Persian پنج (panj), Sanskrit पञ्च(páñca)). Doublet of cinque, punch, pimp, and Pompeii.
The nasal *m in Proto-Germanic *fimf was lost through a sound change known as the Ingvaeonic nasal spirant law.
etymonline
five (adj., n.)
"1 more than four; the number which is one more than four; a symbol representing this number;" Old English fif "five," from Proto-Germanic *fimfe (source also of Old Frisian fif, Old Saxon fif, Dutch vijf, Old Norse fimm, Old High German funf, Gothic fimf), from PIE root *penkwe- "five." The lost *-m- is a regular development (compare tooth).
Five-and-ten (Cent Store) is from 1880, American English, with reference to prices of goods for sale. Five-star (adj.) is from 1913 of hotels, 1945 of generals. Slang five-finger discount "theft" is from 1966. The original five-year plan was 1928 in the U.S.S.R. Five o'clock shadow attested by 1937.
[under picture of a pretty girl] "If I were a man I'd pay attention to that phrase '5 O'Clock Shadow.' It's that messy beard growth which appears prematurely about 5 P.M." [advertisement for Gem razors and blades in Life magazine, May 9, 1938]
