c. 1300, from Old French hauberc "coat of mail," earlier holberc, from Frankish *halsberg or a similar Germanic source, literally "neck-cover" (cognates: Old English halsbearh, Old High German halsberc). The second element is *bergan "to cover, protect" (from PIE root *bhergh- (1) "to hide, protect"). The first is *hals "neck," (source also of Old English, Old Norse, Danish, Swedish, Dutch, German, Gothic hals, from PIE root from PIE root *kwel- (1) "revolve, move round; sojourn, dwell."
It is the hypothetical source of/evidence for its existence is provided by: Old English Old English borgian "to lend, be surety for;" Old Church Slavonic brěgo "I preserve, guard," Lithuanian bìrginti "be parsimonious." But, absent other possible cognates, Boutkan writes that it is not certainly Indo-European and "probably a substratum word."
It forms all or part of: accolade; ancillary; atelo-; bazaar; bicycle; bucolic; chakra; chukker; collar; collet; colonial; colony; cult; cultivate; culture; cyclamen; cycle; cyclo-; cyclone; cyclops; decollete; encyclical; encyclopedia; entelechy; epicycle; hauberk; hawse; inquiline; Kultur; lapidocolous; nidicolous; palimpsest; palindrome; palinode; pole (n.2) "ends of Earth's axis;" pulley; rickshaw; talisman; teleology; telic; telophase; telos; torticollis; wheel.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit cakram "circle, wheel," carati "he moves, wanders;" Avestan caraiti "applies himself," c'axra "chariot, wagon;" Greek kyklos "circle, wheel, any circular body, circular motion, cycle of events,"polos "a round axis" (PIE *kw- becomes Greek p- before some vowels), polein "move around;" Latin colere "to frequent, dwell in, to cultivate, move around," cultus "tended, cultivated," hence also "polished," colonus "husbandman, tenant farmer, settler, colonist;" Lithuanian kelias "a road, a way;" Old Norse hvel, Old English hweol "wheel;" Old Church Slavonic kolo, Old Russian kolo, Polish koło, Russian koleso "a wheel."