ADJECTIVE (2)

1. resembling a uncle in kindness or indulgence;

2. being or relating to an uncle;

The Collaborative International Dictionary of English v.0.48:

Avuncular \A*vun"cu*lar\, a. [L. avunculus uncle.]
   Of or pertaining to an uncle.
   [1913 Webster]

         In these rare instances, the law of pedigree, whether
         direct or avuncular, gives way.          --I. Taylor.
   [1913 Webster]