Winnipesaukee has been translated from the Abenaki to the English language many different ways. Because Abenaki was exclusively an oral language, not a written one, there has been much disagreement among scholars not only to the spelling, but also to the meaning, of various Abenaki words.
According to Bruce Heald, an author who has written extensively about the Lakes Region, the most common translation, "The Smile of the Great Spirit", is based on an old Indian folk tale told about the Lake, as well as the older, alternate spelling of the Lake, Winnipiseogee, with "Winni" meaning "Smiling" and "Ogee" meaning "Great Spirit". (Lake Winnipesaukee, Arcadia Publishing, 2001.)
Chandler E. Potter, in his 1856 history of Manchester, translates the name as meaning "Beautiful Water in a High Place". He explains that Winnepesaukee is derived from "Winne" (beautiful), "Nipe" (water), "Kees" (high), and "Auke" (a place), meaning literally, "the beautiful water of the high place".
Chester B. Price, in his 1967 article Historic Indian Trails of New Hampshire, wrote that, according to the "eminent Indianologist" Father Jeremiah O'Brien, "who spent several months at the Indian reservations", the Abenaki language defined "Winn" as "Outlet", which meant "where the water flows out". This would more closely tie the name of the Lake to Weirs Beach, which was the principal Indian village on the Lake, and the outlet of the Lake.
However, acccording to Price, Winnipesaukee is actually a derivation from the Indian word Wiwininebesaki, which means "at the lake in the vicinity of which there are other lakes and ponds", or literally, "Lakes Region", from "wiwini" (around, in the vicinity), "nebes" (lakes or ponds), and "aki" (region or territory).
C. Lawrence Bond, in his 1991 book, Native Names of New England Towns and Villages, states that Winnipesaukee means "Good Smooth Water at Outlet", deriving it from "Winne" (smooth), "pe~(nip)pe" (water), and "saukee" (outlet). Bond explains, "At its outlet the Winnipesaukee River is smooth where it joins the Pemigewasett (extended seething place) River. The Indians liked to contrast names...the lake was obviously named for the river."
Frederick Matthew Wiseman, in his 2001 book, Voices of the Dawn: An Auto-History of the Abenaki Nation, lists the Abenaki name of the Lake as Wiwinebesaki, meaning "Land Around Lake", and the Abenaki name of Weirs Beach as Wiwinebesakik, meaning "Land Around Lake Place".
In conclusion, there are at least five conflicting interpretations of the meaning of the name of the Lake!
Below, an illustration, "The Spirit's Smile", from M.F. Sweetser's 1889 guide, Here and There in New England and Canada: Lakes and Mountains, published by the Passenger Department of the Boston & Maine Railroad.