An Etymological Dictionary of the German Language/beilen
beilen, vb., ‘to bring deer to a stand by baying,’ formed from MidHG. and OHG. bîl, ‘the moment when the deer stands at bay; encircling by the baying hounds’; MidHG. bîlen, ‘to bring to a stand by baying,’ intr. ‘to bark’. No kinship with bellen can be proved; it is more probably connected with the root bî in beben (for a derivative in l from the latter word comp. Lett. baile, ‘fear,’ bailùs, ‘timid,’ Sans. bltrú, ‘timid’, Sans. bhîrú, ‘timid’). In that case MidHG. and OHG. bî-l would be lit. ‘time of fear.’