frown: [14] Probably the underlying notion of frowning is ‘snorting’ rather than ‘wrinkling the brows’. It comes from Old French froignier, which meant ‘snort’ as well as ‘frown’. It is assumed to have been adopted into French from a Celtic language of Gaul, and would therefore have been related to Welsh ffroen ‘nostril’. [frown etymology, frown origin, 英语词源]