Here are some common meanings of medical prefixes:
* A- or An- (G) from, without: asepsis, without infection.
* A- or Ab- (L) away, lack of: abnormal, departing from normal.
* Ad- (L) to, toward, near: adrenal, near the kidney.
* Ambi- (L) both: ambidextrous, referring to both hands.
* Ante- (L) before: antenatal, occurring or having been formed before birth. Anti- (G) against: antiseptic, against or preventing sepsis.
* Auto- (G) self: auto-intoxication, poisoning by toxin generated in the body.
* Bi- or Bin- (L) two: binocular, pertaining to both eyes.
* Brady- (G) slow: bradycardia, abnormal slowness of heartbeat.
* Circum- (L) around: circumocular, around the eyes.
* Contra- (L) against, opposed: contraindication, indication opposing usually indicated treatment.
* Counter- (L) against: counterirritation, an irritation to relieve some other irritation (e.g., a liniment) .
* Di- (L) two: diphasic, occurring in two stages or phases.
* Dis- (L) apart: disarticulation, taking joint apart.
* Dys- (G) pain or difficulty: dyspepsia; impairment of digestion.
* Ecto- (G) outside: ectoretina, outermost layer of retina.
* Em- or En- (G) in: encapsulated, inclosed in a capsule.
* End- (G) within: endothelium, layer of cells lining heart, blood and lymph vessels.
* Epi- (G) above or upon: epidermis, outermost layer of skin.
* Erythro- (G) red: erythrocyte, red blood cell.
* Eu- (G) well: euphoria, well feeling, feeling of good health.
* Ex- or E- (L) out: excretion, material thrown out of the body or the organ.
* Exo- (G) outside: exocrine, excreting outwardly (opposite of endocrine) .
* Extra- (G) outside: extramural, situated or occurring outside a wall.