'arbitrarily-split' originates from the combination of 'arbitrary' and 'split', where 'arbitrary' comes from Latin 'arbitrarius', meaning 'dependent on the will', and 'split' is derived from Middle English 'spliten', meaning 'to divide'.

'arbitrarily' changed from the Latin word 'arbitrarius' and 'split' from Middle English 'spliten', eventually forming the modern English term 'arbitrarily-split'.

Initially, 'arbitrarily' meant 'dependent on the will', and 'split' meant 'to divide'. Over time, 'arbitrarily-split' evolved to mean 'divided in a random manner'.