An avener ( /ˈævənər/), or avenor, was the chief officer of the stables of a king, and the officer in charge of obtaining positions for horses belonging to the king. The Latin version of the word was avenarius, from the Latin avena, meaning "oats" or "straw". The avenar was under the watch of the Master of the Horse, and in his duties administered the oaths of office to all other stable officials. He was also in charge of stable expense accounts and payroll.
An avenary, related to an avener, was the largest department in the household of the king. There was generally a staff of 100 to 200 valets and grooms which, under the watch of the avenar, tended to the horses of the king, his household, officials and attendants, as well as the horses of royal visitors.