The compound adjective "sun-splashed" is a vivid, poetic creation of Modern English, blending the concrete noun "sun" with the dynamic verb "splash." The core logic hinges on a metaphorical extension: just as liquid splashed onto a surface creates bright, scattered patches, sunlight perceived as being "splashed" onto a scene creates areas of intense, dappled illumination. This figurative use of "splash" to describe the effect of light emerged in the 19th and 20th centuries, capitalizing on the verb's connotations of vigor, abundance, and random distribution. The appended "-ed" suffix functions adjectivally, solidifying the phrase into a stable descriptor for landscapes, interiors, or moments that are brilliantly and vividly lit, as if by a liquid application of sunlight.

Structure: sun (the star) + splash (to scatter liquid) + ed (adjective-forming suffix) - sun: From Old English sunne, of Germanic origin; related to Dutch zon and German Sonne. The central star that gives light and heat to the earth. - splash: Of imitative origin, suggesting the sound and motion of liquid being scattered. The verb means to cause a liquid to scatter in drops. - ed: A suffix forming adjectives from nouns or verbs, indicating 'having the characteristics of' or 'being in a state of'.