The Collaborative International Dictionary of English v.0.48:

Ann \Ann\, Annat \An"nat\, n. [LL. annata income of a year,
   also, of half a year, fr. L. annus year: cf. F. annate
   annats.] (Scots Law)
   A half years's stipend, over and above what is owing for the
   incumbency, due to a minister's heirs after his decease.
   [1913 Webster]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

ANN
       Artificial Neural Networks (NN)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

ANN, Scotch law. Half a year's stipend over and above what is owing for the
incumbency due to a minister's relict, or child, or next of kin, after his
decease. Wishaw. Also, an abbreviation of annus, year; also of annates. In
the old law French writers, ann or rather an, signifies a year. Co. Dig h.v.