light-bulb

The compound 'light-bulb' is a transparent, descriptive term formed in the era of electrical invention. The first element, 'light', traces back to the Proto-Germanic 'leuhtą', carrying the fundamental sense of brightness and visibility. The second element, 'bulb', originates from the Greek 'bolbos', via Latin, referring to a rounded, swelling root or tuber, a shape metaphorically applied to the glass enclosure of early electric lamps. The logic of the term is perfectly literal: an object shaped like a bulb (a rounded vessel) whose function is to produce light, seamlessly combining form and function into a single, iconic noun.

Structure: light (illumination) + bulb (rounded object) - light: From Old English 'lēoht', of Germanic origin; related to Dutch 'licht' and German 'Licht'. Functions as the core semantic element denoting illumination or the agent of making visible. - bulb: From Latin 'bulbus', meaning 'onion, bulb', via Greek 'bolbos' (plant with a swelling underground stem). Functions as the shape-describing element, referring to the rounded, swollen form of the object.