lupus, lup- +

1. Having the nature or qualities of a wolf; such as, being rapacious, predatory, and ravenous.
2. A reference to a wolf or to wolves.
3. Wildly hungry or greedy in behavior or character like a wolf.
4. Any of numerous plants belonging to the genus Lupinus, of the legume family; such as Lupine albus (white lupine), of Europe, bearing edible seeds, or Lupine perennis, of the eastern U.S., having tall, dense clusters of blue, pink, or white flowers.

A reference to or resembling lupus.

Howling in the manner of wolves.

A statement made by St. Cyril describing the horde of Magyars he met in 860 A.D. when they raided deep into Frankish Europe.

1. In medicine, a tuberculous disease of the skin because it was thought that the ulcerations resembled a wolf's bite.
2. A rare form of tuberculosis of the skin, characterized by brownish tubercles that often heal slowly and leave scars.
3. Any of several diseases, especially systemic lupus erythematosus, that principally affect the skin and joints but often also involve other systems of the body.
4. In astronomy: the Wolf, a southern constellation between Centaurus and Norma.

To set a fox to keep the geese.

Don't get a fox to guard the geese [or chickens, ducks, etc.].

To hold a wolf by the ears.

Implies fearlessness in confronting a dangerous situation or boldness in dealing with a difficult situation.