"body of water," early 12c., from Old French lack and directly from Latin lacus "pond, lake," also "basin, tank," related to lacuna "hole, pit," from PIE *laku- (cognates: Greek lakkos "pit, tank, pond," Old Church Slavonic loky "pool, puddle, cistern," Old Irish loch "lake, pond"). The common notion is "basin." There was a Germanic form of the word, which yielded cognate Old Norse lögr "sea flood, water," Old English lacu "stream," lagu "sea flood, water," leccan "to moisten" (see leak, v.). In Middle English, lake, as a descendant of the Old English word, also could mean "stream; river gully; ditch; marsh; grave; pit of hell," and this might have influenced the form of the borrowed word. The North American Great Lakes so called from 1660s.

"deep red coloring matter," 1610s, from French laque (see lac), from which it was obtained.