The Collaborative International Dictionary of English v.0.48:

Lesion \Le"sion\ (l[=e]"zh[u^]n), n. [F. l['e]sion, L. laesio,
   fr. laedere, laesum, to hurt, injure.]
   A hurt; an injury. Specifically:
   (a) (Civil Law) Loss sustained from failure to fulfill a
       bargain or contract. --Burrill.
   (b) (Med.) Any morbid change in the exercise of functions or
       the texture of organs. --Dunglison.
       [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

119 Moby Thesaurus words for "lesion":
   abrasion, abscess, ache, aching, aposteme, bed sore, blain, bleb,
   blemish, blister, blow, boil, break, bubo, bulla, bunion, burn,
   canker, canker sore, carbuncle, chafe, chancre, chancroid, check,
   chilblain, chip, cold sore, concussion, crack, crackle, cramp,
   craze, cut, distress, dolor, eschar, felon, fester, festering,
   fever blister, fistula, flash burn, fracture, fray, frazzle,
   furuncle, furunculus, gall, gash, gathering, grief, gumboil,
   hemorrhoids, hurt, incision, injury, kibe, laceration,
   mortal wound, mutilation, nasty blow, pain, pang, papula, papule,
   paronychia, parulis, passion, petechia, piles, pimple, pock, polyp,
   puncture, pustule, rent, rip, rising, run, rupture, scab, scald,
   scorch, scrape, scratch, scuff, second-degree burn, shock, slash,
   soft chancre, sore, sore spot, spasm, stab, stab wound, stigma,
   stress, stress of life, stroke, sty, suffering, suppuration,
   swelling, tear, tender spot, third-degree burn, throes, trauma,
   tubercle, ulcer, ulceration, wale, welt, wheal, whelk, whitlow,
   wound, wounds immedicable, wrench