seòl

I

method, way, Irish seól a method of doing a thing, seólaim, I direct, steer; Early Irish seól, course; Welsh hwyl, course, condition. From seól, sail.

II

a sail Irish seól, Old Irish séol, seól, seol, g. siúil, Welsh hwyl, Old Welsh huil: usually referred to *seghlo- (root of seagh) or to Teutonic seglo-, sail (also from *seghlo-), borrowed into Celtic. In either case we should expect Irish *sél, Welsh *hail, but we have neither. Strachan suggests that seól is formed from g. siúil on the analogy of ceól, etc.; while Welsh hwyl may have been effected by a borrow from Latin vêlum (Cornish guil, Breton goel).