the word 'undiluted' is a modern english formation built upon the older adjective 'diluted'. the core, 'diluted', originates from the latin verb 'diluere', a compound of 'dis-' (apart) and 'luere' (to wash), conveying the sense of washing something away to thin it out. the old english prefix 'un-', a common negator, was attached to this base, creating a direct and logical meaning of "not having been made thinner or weaker". this etymological construction perfectly mirrors the word's modern applications, describing both physical mixtures that are pure and concentrated, and abstract qualities like emotions or truths that are presented in their full, unmoderated intensity.

Structure: un (not) + diluted (made thinner or weaker) un- (old english, a prefix expressing negation or reversal); diluted (from latin 'diluere' meaning 'to wash away, dissolve', past participle form used as an adjective).