The Collaborative International Dictionary of English v.0.48:

Average \Av"er*age\, v. t. [imp. & p. p. Averaged (?); p. pr.
   & vb. n. Averaging.]
   1. To find the mean of, when sums or quantities are unequal;
      to reduce to a mean.
      [1913 Webster]

   2. To divide among a number, according to a given proportion;
      as, to average a loss.
      [1913 Webster]

   3. To do, accomplish, get, etc., on an average.
      [1913 Webster]