An Etymological Dictionary of the German Language/schnappen
schnappen, vb., ‘to snap, snatch,’ from MidHG. (MidG.) snappen, ‘to snap, chatter.’ The latter, like Du. snappen (E. to snap), is an intensive of MidHG. snaben, ‘to snap, snort’; allied to the root snab contained in Schnabel. — ModHG. schnappen (dial.), ‘to limp,’ MidHG. snappen, ‘to stumble,’ is etymologically distinct from this verb.