Proto-IE: *knap-/-e- (-ph-), -b-
Meaning: to scratch, to scrape
Old Greek: ion., altatt. knáptō `Tuch walken, Wolle krempeln; zerreissen zerfleischen'; knápho-s m. `die Karde des Walkers; Klette, Stachelfolter', knaphéu̯-s `Walker'
Russ. meaning: скрести, царапать
References: WP I 392 f