"the sun,"
c.1450,
from L. sol "the sun,"
from PIE *s(e)wol-,
from base *saewel- "to shine, the sun"
(cf. Skt. suryah, Avestan hvar "sun, light, heavens;"
Gk. helios; Lith. saule; O.C.S. slunice; Goth. sauil,
O.E. sol "sun," swegl "sky, heavens, the sun;"
Welsh haul, O.Cornish heuul, Breton heol "sun;" O.Ir. suil "eye").
The PIE element -*el- in the root originally was a suffix and had an alternate form -*en-, yielding *s(u)wen-, source of Eng. sun (q.v.).