the word 'undetectable' is a modern english formation built from established morphemes. its core, 'detect', originates from the latin verb 'detegere', meaning 'to uncover' or 'to expose', which itself is composed of 'de-' (off, away) and 'tegere' (to cover). the suffix '-able', of latin origin, was added to form the adjective 'detectable', meaning 'capable of being uncovered or discovered'. finally, the old english negative prefix 'un-' was prefixed to create the current meaning of 'not capable of being discovered'. the word's logical construction perfectly mirrors its modern abstract sense, describing something that cannot be found or perceived.

Structure: un (not) + detect (discover) + able (capable of) un- (old english, a prefix meaning 'not'), detect (from latin 'detectus', past participle of 'detegere' meaning 'to uncover'), -able (from latin '-abilis', a suffix forming adjectives meaning 'capable of, fit for').