glabrous

Before them an old man, / wearing a fringe of long white hair, bareheaded, / his glabrous skull reflecting the sun's / light.... No question about it - the bald crown of an old man's head (as described here in William Carlos Williams's poem "Sunday in the Park") is "a surface without hairs." William's use isn't typical, though. More often "glabrous" appears in scientific contexts, such as the following description of wheat: "The white glumes are glabrous, with narrow acuminate beaks." And although Latin glaber, our word's source, can mean simply "bald," when "glabrous" refers to skin with no hair in scientific English, it usually means skin that never had hair (such as the palms of the hands).