the word 'unremarked' is a modern english formation built upon the older verb 'remark', which entered english from middle french 'remarquer', meaning to observe or take note of. the french term itself is a compound of the latin prefix 're-' (expressing intensive force or repetition) and a germanic root related to 'mark'. the addition of the negative prefix 'un-' creates a straightforward meaning of "not noticed". the logic of its construction is transparent: something that has not been observed or commented upon, even upon a second or closer look.

Structure: un (not) + re (again) + marked (noticed) un: a prefix of germanic origin (old english) meaning "not". re: a prefix of latin origin meaning "again" or "back". marked: from the verb 'mark', of old english origin, meaning to notice or observe.