ulcer

a circumscribed inflammatory and often suppurating lesion on the skin or an internal mucous surface resulting in necrosis of tissue

A solution of continuity in any of the soft parts of the body, discharging purulent matter, found on a surface, especially one of the natural surfaces of the body, and originating generally in a constitutional disorder; a sore discharging pus. It is distinguished from an abscess, which has its beginning, at least, in the depth of the tissues.