Is English "lake" Derived from Latin, or is it Indo-European?

Question

I'm having a bit of trouble figuring this one out.

Lake, meaning "A large, landlocked stretch of water." seems to have some confusion in the Wiktionary pages. I've looked in the American Heritage Dictionary, as well as the Oxford English Dictionary and they both state something along the lines of:

"Early Middle English lac , < Old French lac, < Latin lacus basin, tub, tank, lake, pond"

and:

"[Middle English, from Old French lac and from Old English lacu, both from Latin lacus.]"

However, the Wiktionary on page seems to make exception to this and states:

"From Middle English lake (“lake, watercourse, body of water”), from Old English lacu (“lake, pond, pool, stream, watercourse”), from Proto-Germanic lakō, lōkiz (“stream, pool, water aggregation", originally "ditch, drainage, seep”), from Proto-Germanic lekaną (“to leak, drain”), from Proto-Indo-European leg-, leǵ- (“to leak”)."

It even goes on to address this and states:

"Despite their similarity in form and meaning, English lake is not related to Latin lacus (“hollow, lake, pond”)"

I know Wikipedia sources can sometimes be questionable, but I would like to not be confused about this.

Answer 1

The word is without doubt Indo-European, the question is whether it is strictly Germanic or did it come via Latin. Pokorny says *laku is the source of Gr. λάκκος, lat. lacus, OIr. loch, and lagu etc. in Germanic: see the Texas collection for more attestations, which includes English "lake". For *leg, the "leak" root, Pokorny gives Armenian, Celtic and Germanic only; the Texas elaboration relates that root to "lack; leak", and nothing like "lake". (leĝ would be a different root meaning "collect"). Texas lists lagu-lad, lago for OE and not lacu. I would be inclined to believe Texas and Pokorny (and AHD) over Wiki (also bearing in mind that the Texas list for Modern English gives all related words, no matter how they got there). But there's more.

There is at least one other vote, the Oxford English Dictionary. It gives two entries for modern English "lake". One, which they list in its earliest form as lac, has the sense "A large body of water entirely surrounded by land", attested c1275 (▸?a1200) in Laȝamon Brut (Calig.) (1963) l. 642 "Ouer þen lac [c1300 Otho lake] of Siluius & ouer þen lac [c1300 Otho lake] of Philisteus", and a1225 St. Marher. 14 "Ich leade ham..iþe ladliche lake of the suti sunne". This is the ordinary use of "lake". They say of the contemporary word

The present English form lake (recorded from the 14th cent.) may be due to confusion with lake n.3, or perhaps rather to independent adoption of Latin lacus.

Another sense lake n.3 is "A small stream of running water", is attested as OE lacu, citing the attestation from 955 Charter of Edred in Earle Charters 382 Ðæt to Mægðe forda andlang lace ut on Temese. This they say is not from Latin lacus because of the meaning, and they derive the word from the "leak" root *leg. A half-vote also goes to Etymologyonline, which lists both roots, says that the modern word is borrowed, and gives both Old English lacu "stream, pool, pond" and lagu "sea flood, water, extent of the sea" (lagu being the OE form cited in Pokorny).

In other words, the weight of evidence indicates that it is borrowed (in some fashion, including adaptation of semantics), the source would be French (hence Latin), and that it is the result of two distinct roots.

Answer 2

The Old English word 'lagu' is retained in English as the word as 'law'. Judgement, and bodies of water are connected in ancient English culture.

In around 90AD, sacrifices were made to the goddess Nerthus (according to Tacitus) by drowning the chosen in the lagu as they were subject to the lagu. This was happening when the Angles occupied Jutland.

The origin of the concept word for lake, lagu and law, and perhaps also loch (?) are pre-Latin and pre-Germanic.