'explicability' originates from Late Latin, specifically the word 'explicabilitas', where 'explicare' meant 'to unfold, explain' and suffixes like '-abilis'/'-ity' indicated 'able' and 'state or quality'.

'explicabilitas' passed into Medieval/Modern usage via forms such as Latin 'explicabilis' and the adjective 'explicable', and the noun 'explicability' was formed in English by adding the nominalizing suffix '-ity' to 'explicable'.

Initially it denoted 'the state of being able to be unfolded or explained', and over time it has come to mean more generally 'the quality of being explainable or capable of being made intelligible'.