Etymology: The senses here included appear to belong to the same original word, though this, from want of early evidence, is not quite proved. Sense 1 is found only in Old English as cumb ; sense 2 is found from 14th to 17th centuries, in form comb , combe ; its pronunciation is unfortunately unknown; sense 3 begins a1500, and has the forms comb, combe, coomb, pronounced /kuːm/. Old English cumb was probably identical with older Low German kumb, High German kump; compare modern Low German and High German kumm a vessel, in various dialects, a round deep vessel, basin, cistern, trough, etc. (also modern German kumme, older probably kumbe). Besides this modern German has kumpf, Low German kump, a vessel (in many senses), a measure of corn and fruit, ¹/ ₁₆ of a malter, i.e. an English peck nearly. The Bremen Wörterbuch identifies the two Low German forms: ‘kumm oder besser kump, tiefe schüssel’: so that we have apparently an Old Germanic type *kumbo-, *kummo-, with by-form *kumpo- (as in clam, clamp), with general sense of vessel, or hollowed-out receptacle. As to the phonetic history, the vowel of Old English cumb was apparently lengthened before mb as in comb , climb , clomb , with similar loss of b , and the ū sound preserved in modern English instead of being diphthongized, as in Old English rúm , Middle English roum , modern room n.¹ and int. Compare also coop n.¹

Etymology: In Old English, cumb masculine ‘small valley, hollow’ occurs in the charters, in the descriptions of local boundaries in the south of England; also in numerous place-names which still exist, as Batancumb Batcombe, Brancescumb Branscombe, Eastcumb Eastcomb, Sealtcumb Salcombe, Wincelcumb Winchcombe, etc. As a separate word it is not known in Middle English literature, but has survived in local use, in which it is quite common in the south of England: see sense 1b. In literature coomb appears in the second half of the 16th cent., probably introduced from local use; a century later, it was still treated by Ray as a local southern word. Old English cumb is usually supposed to be of British origin: modern Welsh has cwm (ku m) in the same sense, also in compound place-names as -cwm , -gwm , and in syntactic combination as Cwm Bochlwyd . A large number of place- names beginning with Cum- , especially frequent in Cumbria, Dumfriesshire, and Strathclyde, as Cumwhitton , Cumdivock , Cumlongan , Cumloden , appear to be thus formed. Welsh cwm represents an earlier cumb , Old Celtic *kumbos . The Old English word might however be an obvious application of cumb , coomb n.¹, to a physical feature, though there is no trace of any such application of the cognate German words on the Continent; in any case, if the Saxons and Angles found a British cumb applied to a hollow in the ground, its coincidence with their own word for ‘basin, bowl, deep vessel’ would evidently favour its acceptance and common use. This might further be strengthened, after the Norman Conquest, by the existence of < French combe ‘petite vallée, pli de terrain, lieu bas entouré de collines’ (Littré, 12th cent.), cognate with Provençal comba , Spanish comba and north Italian comba , for which also a Celtic origin has been claimed. See Diez, Thurneysen, Littré. The phonetic history is the same as in coomb n.¹; in compounds (in names of old formation) /-kuːm/ has sunk to /-kəm/.