Etymology: Old English coss = Old Frisian kos, Old Saxon cos, kus (Middle Dutch cus, cuss, Dutch kus), Old High German chus (Middle High German kus, kos, German kuss), Old Norse koss < Old Germanic *kuss-oz. Middle English cuss/kʊs/ was apparently developed < coss, as it appears to have had /ʊ/ not /ʏ/, and occurs in texts which do not use cusse (cüsse) for the verb. The modern English form (like Danish kys, Swedish kyss) is from the verb.

Etymology: Old English cyssan (past tense cyste , past participle cyssed ) = Old Frisian kessa , Old Saxon kussian (Middle Dutch cussen , Dutch kussen ), Old High German chussen , kussen (Middle High German and German küssen ), Old Norse kyssa (Swedish kyssa , Danish kysse ) < Old Germanic *kussjan , < *kuss- : see kiss n. Both verb and noun are wanting in Gothic, which has, in the same sense, kukjan (compare East Frisian kükken ). Of the Middle English forms those in y , i , were originally Midland and Northern; of those in u , the earlier, down to c1400, had ü as regular southern Middle English representation of Old English y ; the later (in u not ü ) are to be compared with the form kuss of kiss n.; those in e have partly e < ü as in Kentish; partly e as a broadening of i. The rare Old English cossian (past tense cossode), was a distinct formation, from the noun; but the later examples (14–16th cent.) of coss, koss, appear to be merely the ordinary verb assimilated to the noun in its vowel.