The word 'sunbather' is a modern English compound formed from three distinct elements. The first, 'sun', originates from the Old English sunne, a term for the radiant celestial body, which has been a central concept in Germanic languages. The second element, 'bath', derives from Old English bæð, referring to the act of washing or immersing oneself, typically in water. The final agent suffix '-er' is a productive English morpheme denoting a person performing an action. The compound's logic is transparently metaphorical: it describes a person who 'bathes' in the sun's rays as if they were water, engaging in the activity for leisure or to darken the skin. This term emerged in the 20th century, reflecting the cultural practice of recreational sun exposure.

Structure: sun (star) + bath (wash) + er (agent suffix) - sun: From Old English sunne, of Germanic origin; related to Dutch zon and German Sonne. The celestial body that gives light and heat. - bath: From Old English bæð, of Germanic origin; related to Dutch bad and German Bad. The act of washing or immersing in water. - er: A native English suffix forming agent nouns from verbs, indicating "a person or thing that does something."