the word 'unexplainable' is a modern english formation built upon the verb 'explain,' which entered english from latin explanare ("to flatten out, make clear"). the latin term itself is a compound of ex- ("out") and planus ("flat, level"), suggesting the metaphorical act of smoothing out or clarifying a concept. the suffix '-able,' of latin origin, was attached to create the adjective 'explainable,' meaning "capable of being made clear." finally, the old english negative prefix 'un-' was prefixed to negate this capability, resulting in the current meaning of something that cannot be clarified or accounted for. this construction demonstrates the layered, hybrid nature of english vocabulary, combining germanic and latinate elements.

Structure: un (not) + explain (make clear) + able (capable of) - un: a prefix of germanic origin (old english) meaning "not," used to form negatives. - explain: a verb of latin origin (from explanare, meaning "to make level, make clear") serving as the core lexical root. - able: a suffix of latin origin (via old french, from latin -abilis) meaning "capable of, fit for," used to form adjectives.