Lewis

From Middle English Lewis, Lowis, from Anglo-Norman, from Old French Louis, from Frankish *Hlūdawīg. Doublet of Louis.

An anglicization of Irish Lobhaois, itself from Old French Louis.

An adopted anglicization of Welsh Llywelyn, from Old Welsh, from Proto-Brythonic *Lluɣβelen, from Proto-Celtic *Lugus + *Belinos, whose origin is disputed; see Belenus.

Derived from Scottish Gaelic Leòdhas, of uncertain origin; traditionally referred to Old Norse Ljóðahús, from ljóð (“song, poem”) + hús (“house”); but may be related to the Pictish name of the island recorded in Ptolemy's Geography as Λίμνου (Límnou).