lacū
lacu f
From Latin lacus.
lacu m
From Proto-Germanic *lakō, *lakiz (“stream, pool, water aggregation", originally "ditch, drainage, seep”), from Proto-Germanic *lakjaną (“to water, wet, irrigate, drain”), causative of Proto-Germanic *lekaną (“to leak, drain”), from Proto-Indo-European *leǵ- (“to leak”). Cognate with Old Saxon laca (in placenames, “lake, stream, brook”), Old High German lacha (“pool, water collected in a ditch, swamp”), Middle Dutch lāke (“pond, lake, stream, brook”), Middle Low German lāke (“water pooled in a riverbed”), Old Norse lækr (“slow flowing stream”), Old English leċċan (“to make wet, moisten”), Old Norse leka (“to drip, leak”). More at leak.