Lake
late Old English (denoting a pond or pool), from Old French lac, from Latin lacus ‘basin, pool, lake’.
wiktionary
Arose from a contamination of the form of inherited Middle English lake(“small stream of running water, pool, lake”) with Middle English lac(“lake”), from Old French lac(“lake”) or Latin lacus(“lake, basin, tank”). The former, lake(“stream, pool, lake”), is inherited from Old English lacu(“stream, pool, expanse of water, lake”), from Proto-West Germanic *laku, from Proto-Germanic *lakō(“stream, pool, water aggregation”), ultimately derived from Proto-Indo-European *leg-(“to leak, drain”). It is related to Dutch laak(“stream, drainage ditch, pond”), German Low German Lake, Laak(“drainage, marshland”), German Lache(“puddle”), Icelandic lækur(“stream”). [1]
Despite their similarity in form and meaning, the word is not related to English lay(“lake”), Latin lacus(“hollow, lake, pond”), Scottish Gaelic loch(“lake”), Ancient Greek λάκκος(lákkos, “waterhole, tank, pond, pit”), all from Proto-Indo-European *lókus, *l̥kwés(“lake, pool”). [2]
From Middle English lake, lak, lac (also loke, laik, layke), from Old English lāc(“play, sport, strife, battle, sacrifice, offering, gift, present, booty, message”), from Proto-Germanic *laiką(“play, fight”), *laikaz(“game, dance, hymn, sport”), from Proto-Indo-European *leyg-, *loig-, *leig-(“to bounce, shake, tremble”). Cognate with Old High German leih(“song, melody, music”). Verb form partly from Middle English laken, from Old English lacan, from Proto-Germanic *laikaną, from Proto-Indo-European *leyg-. More at lay, -lock.
From Middle English lake, from Old English *lacen or Middle Dutch laken; both from Proto-Germanic *lakaną(“linen; cloth; sheet”). Cognate with Dutch lake(“linen”), Dutch laken(“linen; bedsheet”), German Laken, Danish lagan, Swedish lakan, Icelandic lak, lakan.
From French laque(“lacquer”), from Persian لاک (lâk), from Hindi लाख(lākh), from Sanskrit लक्ष(lakṣa, “one hundred thousand”), referring to the number of insects that gather on the trees and make the resin seep out. Doublet of lakh.
etymonline
lake (n.1)
"body of water surrounded by land and filling a depression or basin," early 12c., from Old French lack (12c., Modern French lac) and directly from Latin lacus "pond, pool, lake," also "basin, tank, reservoir" (related to lacuna "hole, pit"), from PIE *laku- "body of water, lake, sea" (source also of 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 PIE root which yielded Old Norse lögr "sea flood, water," Old English lacu "stream, pool, pond," lagu "sea flood, water, extent of the sea," 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.
lake (n.2)
"deep red coloring matter," 1610s, from French laque (15c., see lac), from which it was obtained.
lake (v.)
"to play, sport," Old English lacan (see lark (n.2)).
