sail (n.) Look up sail at Dictionary.com
Old English segl, from Proto-Germanic *seglom (cf. Swedish segel, Old Norse segl, Old Frisian seil, Dutch zeil, Old High German segal, German Segel), of obscure origin with no known cognates outside Germanic. Irish seol, Welsh hwyl "sail" are Germanic loan-words. Sometimes referred to PIE root *sek- "to cut," as if meaning "a cut piece of cloth."
sail (v.) Look up sail at Dictionary.com
Old English segilan, from the same Germanic source as sail (n.); cognate with Old Norse sigla, Middle Low German segelen, German segeln. Related: Sailed; sailing.