Without a chap or crack; smooth-faced or unwrinkled, particularly used in old texts to describe someone with an unlined face.
From chap (a crack in skin, from Middle English and Middle Dutch) + -less (suffix meaning 'without'). The word chap developed from the cracks that appear in skin from cold or chapping.
Calling someone 'chapless' was a backhanded compliment—it basically meant your face was so young and unblemished that you hadn't yet developed the weathered cracks that come with age and hard work.
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