The Collaborative International Dictionary of English v.0.48:

Naevus \Nae"vus\ (n[=e]"v[u^]s), n.; pl. Naevi (-v[imac]).
   [L.] (Med.)
   A spot or mark on the skin of children when born; a
   birthmark; -- the term includes moles as wells a other types
   of birthmark, and is most commonly applied to reddish or
   brownish raised vascular areas of the skin, i. e., those
   consisting mainly of blood vessels, as dilated arteries,
   veins, or capillaries. [Usually spelled nevus.]
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

nevus
    n 1: a blemish on the skin that is formed before birth [syn:
         birthmark, nevus]

Moby Thesaurus II by Grady Ward, 1.0:

173 Moby Thesaurus words for "nevus":
   benign tumor, bilge, birthmark, blackhead, blain, blaze, bleb,
   blemish, blister, blob, blotch, boss, bow, brand, bubble, bulb,
   bulge, bulla, bump, bunch, burl, button, cahot, callosity, callus,
   cancer, carcinoma, caste mark, check, checkmark, chine, cicatrix,
   clump, comedo, condyle, convex, corn, crack, crater, craze, cut,
   cyst, dapple, defacement, defect, deformation, deformity,
   discoloration, disfiguration, disfigurement, distortion, dot,
   dowel, ear, earmark, engraving, excrescence, fault, flange, flap,
   flaw, fleck, flick, freckle, fungosity, fungus, gall, gash, gnarl,
   graving, growth, hack, handle, hemangioma, hickey, hill, hump,
   hunch, intumescence, jog, joggle, jot, keloid, kink, knob, knot,
   knur, knurl, lentigo, lip, loop, lump, macula, malignant growth,
   mark, marking, metastatic tumor, milium, mole, morbid growth,
   mottle, mountain, needle scar, neoplasm, nick, nonmalignant tumor,
   notch, nub, nubbin, nubble, outgrowth, papilloma, patch, peg,
   pimple, pit, pock, pockmark, point, polka dot, port-wine mark,
   port-wine stain, prick, proud flesh, puncture, pustule, rib, ridge,
   rift, ring, sarcoma, scab, scar, scarification, score, scotch,
   scratch, scratching, sebaceous cyst, shoulder, speck, speckle,
   spine, splash, split, splotch, spot, stain, stigma,
   strawberry mark, stud, sty, style, tab, tattoo, tattoo mark, tick,
   tittle, track, tubercle, tubercule, tumor, twist, verruca, vesicle,
   wale, warp, wart, watermark, weal, welt, wen, whitehead