'explainably' originates from the word 'explainable', which is derived from the verb 'explain'. The prefix 'ex-' means 'out' and the root 'plain' comes from Latin 'planus', meaning 'clear'.

'explainable' evolved from the Latin word 'explanare', which meant 'to make clear'. Over time, it became 'explain' in English, and the adverb form 'explainably' was derived.

Initially, it meant 'to make clear', and over time it evolved into its current meaning of 'in a manner that can be explained'.