Gain a better understanding of medical terminology by searching our dictionary of more than 1,300 terms.


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All terms that start with the letter L
  • labia

    Lip-shaped structures; often used to describe the outer folds of the female genitalia.

  • labyrinth

    The system of interconnecting canals and cavities in the inner ear. Plays an important role in hearing and in…

  • laceration

    A wound caused by a cut from a sharp instrument or the tearing of body tissue.

  • lacrimation

    Discharge of tears. “Watering” eyes.

  • lactase

    An enzyme that converts the milk sugar lactose into glucose and galactose.

  • lactation

    Secretion of milk by the breasts.

  • lactose

    Milk sugar.

  • laryngitis

    Inflammation of the larynx, resulting in a temporary loss of voice.

  • larynx

    The voice box.

  • lateral

    Toward the side, sideways.

  • lavage

    Washing out of an organ, especially the stomach.

  • Legg-Calve-Perthes disease

    Perthes disease A disease in which the blood supply to the femur is reduced, causing the bone to collapse.

  • lens

    1. A curved glass used to bring together or spread rays of light. 2. The transparent organ lying behind the…

  • leprosy

    A progressive infectious disease that attacks the skin, flesh and nerves; characterized by nodules, ulcers, scaly scabs, deformities and the…

  • lesion

    Any damage to a tissue. Marks, spots, moles or other problems of the skin.

  • lethargy

    A lack of energy; sluggishness, dullness or apathy.

  • leukemia

    Cancer of the tissues in the bone marrow, spleen and lymph nodes.

  • leukocytes

    White blood cells, the blood cells responsible for fighting infection.

  • leukopenia

    A lower than normal number of leukocytes in the blood.

  • leukopheresis

    Selective removal of the white blood cells from a donor’s blood. The other components of the blood are then returned…

  • leukoplakia

    Thick, white patches in the mouth that may become malignant.