The word 'stunner' is a derivative of the verb 'stun', which entered English in the Middle English period from Germanic roots. The core concept of 'stun' relates to a state of daze, shock, or overwhelming impact, both physical and mental. By adding the agent suffix '-er', the noun 'stunner' was formed to denote something or someone that causes such a powerful effect. Over time, its meaning specialized, applying not only to shocking events but also, colloquially, to a person whose beauty or impressiveness is metaphorically 'stunning'.

Structure: stun (to shock) + n (infix) + er (agent suffix) - stun: From Middle English stonen, stunen, meaning to be dazed or astonished. Of Germanic origin, related to Old Norse stynja (to groan) and Old High German stunen (to crash). - n: An infix or linking consonant that emerged in the formation of the verb 'stun' from its older forms. - er: An agent noun suffix from Old English -ere, of Germanic origin, used to form nouns denoting a person or thing that performs the action of the verb.