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]

Moby Thesaurus II by Grady Ward, 1.0:

138 Moby Thesaurus words for "animus":
   acrimony, afflatus, aim, ambition, anima, animating spirit,
   animation, animosity, antagonism, antipathy, appetence, appetency,
   appetite, aptitude, aspiration, bad blood, bent, bias,
   bitter feeling, bitterness, cast, character, choice, command,
   conation, conatus, constitution, counsel, decision, desideration,
   desideratum, design, desire, determination, diathesis, discretion,
   discrimination, disposition, divine afflatus, eccentricity, effect,
   elan vital, enlivenment, exhilaration, fancy, feud, fire, firing,
   fixed purpose, free choice, free will, function, genius, grain,
   grudge, hard feelings, hostility, idea, idiosyncrasy, ill blood,
   ill feeling, ill will, inclination, individualism, infection,
   infusion, inspiration, intendment, intent, intention, kidney,
   leaning, liking, lust, make, makeup, meaning, mental set, mettle,
   mind, mind-set, mold, motive, moving spirit, nature, nisus,
   objective, passion, plan, pleasure, pneuma, point, predilection,
   predisposition, preference, prejudice, proclivity, project,
   propensity, proposal, prospectus, psyche, purpose, rancor,
   resolution, resolve, sake, set, sexual desire, slant, soreness,
   sourness, spirit, stamp, strain, streak, stripe, striving, study,
   temper, temperament, tendency, turn, turn of mind, twist, type,
   velleity, vendetta, venom, view, virulence, vital force, vitriol,
   volition, warp, will, will power, wish



The Free On-line Dictionary of Computing (30 December 2018):

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)


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

ANIMUS. The intent; the mind with which a thing is done, as animus
cancellandi, the intention of cancelling; animus farandi, the intention of
stealing; animus maiaendi, the intention of remaining; animus morandi, the
intention or purpose of delaying.
    2. Whether the act of a man, when in appearance criminal, be so or not,
depends upon the intention with which it was done. Vide Intention.