lake in Italy, named for the town along its shore, which is Roman Comum, from Celtic cumba "valley" (compare coomb). Its ancient name was Lacus Larius; Lacus Comacinus begins to appear 4c. It is associated with Virgil and the two Plinys.
Entries linking to como
coomb n.
also combe, "deep hollow or valley, especially on flank of a hill," mainly surviving in place names, from Old English cumb, probably a British word, from Celtic base *kumbos (compare Welsh cwm in same sense). Cambridge Dictionary of English Place-Names says, "This is usually taken to be a Celtic loan ... but there was also OE cumb 'vessel, cup, bowl,'" which was "probably used in a transferred topographical sense reinforced in western districts by cwm."