Menemerus semilimbatus are about 6.5–8.4 millimetres (0.26–0.33 in) long, the male being slightly smaller than the female. These fairly big jumping spiders are dorso-ventrally flattened and are covered with short dense, grayish-white hairs, with hairy whitish palps and a white band on the side margins of the carapace, showing also a small white, triangular marking in the middle. The eyes are large and forward-facing. The legs are light brown with darker rings and patches, while the abdomen is dorsally yellowish or grayish, with a characteristic pattern of several bright V-shaped markings. The females show a notch at the posterior edge of the epigyne and two oval depressions in the anterior half.