An Etymological Dictionary of the German Language/helligen

by Friedrich Kluge

helligen, behelligen, vb., ‘to importunate,’ from MidHG. hęlligen, ‘to weary by pursuit, tease, torment’; a nominal verb from MidHG. hęllic, adj., ‘wearied, exhausted,’ ModHG. hellig, ‘wearied.’ The origin of the adj. is obscure.