lakeyoudaoicibaDictYouDict[lake 词源字典]
lake: English has two words lake. The one meaning ‘body of water’ [13] comes via Old French lac from Latin lacus. This goes back to the same prehistoric source as produced Gaelic loch (acquired by English in the 14th century) and Latin lacūna ‘hole, pit, pool’ (from which English got lacuna [17] and, via Italian or Spanish, lagoon [17]); this seems to have denoted ‘hole, basin’, the notion of ‘water-filled hole’ being a secondary development. Lake the colour [17], now usually encountered only in crimson lake, is a variant of lac, a term for a reddish resin or dye that comes via Dutch or French from Hindi lākh, and forms the second syllable of English shellac.

Its ultimate source is Sanskrit lākshā. Lacquer [16] comes via early modern French lacre ‘sealingwax’ from laca, the Portuguese version of lac.
=> lacuna, lagoon; lacquer, shellac[lake etymology, lake origin, 英语词源]
lake (n.1)youdaoicibaDictYouDict
"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.
lake (n.2)youdaoicibaDictYouDict
"deep red coloring matter," 1610s, from French laque (see lac), from which it was obtained.