'accidentally-disposed' originates from the combination of 'accidentally' and 'disposed'. 'Accidentally' comes from Latin 'accidentalis', meaning 'happening by chance', and 'disposed' from Latin 'disponere', meaning 'to arrange'.

'accidentally-disposed' combines the adverb 'accidentally' and the past participle 'disposed', forming a modern English adjective.

Initially, 'disposed' meant 'arranged or set in order', but in this context, it evolved to mean 'thrown away'.