the word 'sunstroke' is a transparent english compound formed from two native germanic elements. the first element, 'sun', originates from the old english sunne, which has remained remarkably consistent in form and meaning, referring to the star at the center of our solar system. the second element, 'stroke', derives from old english strāc, meaning a blow or strike, a sense that evolved metaphorically to denote a sudden, severe attack of illness. the compound, emerging in the early 18th century, logically constructs its meaning from its parts: an illness that strikes like a blow, specifically caused by overexposure to the sun. this formation exemplifies how english can create precise medical terminology through the figurative combination of simple, concrete words.

Structure: sun + stroke sun: from old english sunne, of germanic origin; related to dutch zon and german sonne, from an indo-european root shared by greek hēlios and latin sol. functions as the noun base denoting the celestial body. stroke: from old english strāc 'a blow', of germanic origin; related to dutch slag and german schlag. in this compound, it functions metaphorically to mean a sudden, damaging attack or seizure.