The Collaborative International Dictionary of English v.0.48:

Animus \An"i*mus\, n.; pl. Animi. [L., mind.]
   Animating spirit; intention; temper.
   [1913 Webster]

   nimus furandi [L.] (Law), intention of stealing.
      [1913 Webster]

WordNet (r) 3.0 (2006):

animus
    n 1: a feeling of ill will arousing active hostility [syn:
         animosity, animus, bad blood]

The Free On-line Dictionary of Computing (19 January 2023):

Animus

    A system described by Robert Adamy Duisberg of the
   University of Washington for creating animations by specifying
   constraints that describe the appearance and structure of
   pictures as well as how those pictures evolve in time.

   ["Constraint-Based Animation: The Implementation of Temporal
   Constraints in the Animus System", Robert Adamy Duisberg, PhD
   Thesis U Washington 1986].

   (1995-11-24)