before 1000; (noun) Middle Englishschakle, schakyl(le); Old Englishsceacel fetter; cognate with Low Germanschakel hobble, Old Norseskǫkull wagon pole, (v.) late Middle Englishschaklyn, derivative of the noun
O.E. sceacel, from P.Gmc. *skakula- (cf. M.Du., Du. schakel "link of a chain," O.N. skökull "pole of a carriage"), of uncertain origin. The common notion of "something to fasten or attach" makes a connection with shake unlikely. The verb is first recorded c.1440. Shacklebolt "bolt which passes through the eyes of a shackle" is recorded from 1688.