French froncer

← German Runzel (cognate)

← Middle Dutch ronse (cognate)

← English ruck (link)

← French fronce (mention)

← Middle French fronce (mention)

← Old French fronces (mention)

← Proto-Germanic *hrunkijō (mention)

← Proto-Germanic *hrunkitō (mention)

← Old High German runza (cognate)

← Proto-Indo-European *sker- (mention)

← Icelandic hrukka (cognate)

← Old Norse hrukka (cognate)

→ Spanish fruncir (borrowed)

→ French froncement (suffix)

→ French renfrogner (mention)