Extremely obvious, clear, or easy to understand; unmistakably evident.
This phrase emerged in the early 1800s American English, building on the natural association between daylight and clarity of vision. It replaced earlier phrases like 'plain as a pikestaff' and reflects the human tendency to equate light with understanding and darkness with confusion or mystery.
The phrase taps into one of our most basic sensory experiences - the dramatic difference between what we can see clearly in daylight versus in darkness. It's interesting that cultures worldwide use similar light-based metaphors for understanding, suggesting this connection between illumination and comprehension is deeply embedded in human cognition.
Complete word intelligence in one call. Free tier — 50 lookups/day.