dorsum. The back, the posterior part of an organ.

drainage. (Surgically) The gradual removal of the contents of a suppurating cavity.

d.s. or s. Used in prescription writing, meaning to give directions.

dynia. Pain, as in pleurodynia, pain in the pleura.

E

ecchymosis. An extravasation of blood or slight hemorrhage under the skin resulting in a purplish patch.

echinococcus. The larval stage of the dog tapeworm, occurring also in human organs or tissues.

ectomy. To cut out, as in prostatectomy, removal of a part or all of the prostate.

eczema. Inflammation of the skin (acute or chronic, moist or dry), accompanied by itching and burning.