French derives sève from Latin sapa (‘sap, juice’), while English arrives at seu/sew via Old English séaw. In both languages the word develops a culinary sense of ‘pottage, broth’ or ‘sauce’, in which context it sometimes seems to have become synonymous with civé (‘onion soup’), formally similar, but from a different etymology (cepa: ‘onion’).

As a result, both the vocalic seue and non-vocalic seve forms are genuine , and, when the sense is ‘onion soup’ there may have been a disyllabic sevé by analogy with civé. The sense ‘moisture’ may also suggest an association with the sudare word-family (cf. suer³, ‘to sweat’); see Möhren Wort- und sachgeschichtliche Untersuchungen an französischen landwirtschaftlichen Texten, 13., 14. und 18. Jahrhundert, p. 253.