underscarf UK /ˈʌndəˌskɑːf/US /ˈʌndɚˌskɑɹf/ noun1 •A tight-fitting headscarf, usually elasticized, that is worn under a hijab or overscarf.White and crisp and full, but pinned over an underscarf, and this underscarf was decorated with lace. — 2010 formsunderscarfs · underscarves