1.  The second rune of the Elder Futhark, representing the letter U.

Uruz is the rune of the Aurochs, or wild ox, and in many ways is akin to FEHU. However, FEHU represents the domesticated, predictable farm cattle, whereas URUZ represents the vital, wild force and energy of the hardy wild ox.

2.  The aurochs was a ferocious native species of wild ox which is now extinct. The energy behind this rune is the life force of the masculine polarity, the unconscious drive for manifestation.

I know a second that the sons of men Must learn who wish to be leeches [i.e., healers]. —Havamal