Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class V. Words Releasing to the Voluntary Powers
Division (I) Individual Volition
Section I. Volition in General
1. Acts of Volition

603. Unwillingness.

   NOUN:UNWILLINGNESS &c. adj.; indisposition, indisposedness, disinclination, aversation [rare], aversion; averseness (dislike) [See Dislike]; nolleity [rare], nolition [rare]; renitence or renitency; reluctance; indifference [See Indifference]; backwardness &c. adj.; slowness [See Slowness]; want of -alacrity, – readiness; indocility (obstinacy) [See Obstinacy].
  SCRUPULOUSNESS, scrupulosity; qualms -, twinge- of conscience; delicacy, demur, scruple, qualm, shrinking, recoil; hesitation (irresolution) [See Irresolution]; fastidiousness [See Fastidiousness].
  DISSENT [See Dissent]; refusal [See Refusal].
  FORCED LABOR, unwilling service, peonage; compulsion [See Compulsion]; slacker.
   VERB:BE UNWILLING &c. adj.; nill [archaic]; dislike [See Dislike]; grudge, begrudge; not find it in one’s heart to, not have the stomach to.
  DEMUR, stick at, scruple, stickle; hang fire, run rusty [colloq.], go stale; give up, let down [slang]; pull back, be a dead weight, be a passenger in the boat, not pull fair, shirk, slack, shy [dial. Eng.], fight shy of, get by [slang], duck [slang]; recoil, shrink, swerve; hesitate [See Irresolution]; avoid [See Avoidance].
  OPPOSE [See Opposition]; dissent [See Dissent]; refuse [See Refusal].
   ADJECTIVE:UNWILLING; not in the vein, loath or loth, shy of, disinclined, indisposed, averse, reluctant, not content; renitent, opposed; adverse (opposed) [See Opposition]; laggard, backward, remiss, slack, slow to; indifferent [See Indifference]; scrupulous; squeamish (fastidious) [See Fastidiousness]; repugnant (dislike) [See Dislike]; restiff [obs.], restive; demurring &c. v.; unconsenting (refusing) [See Refusal]; involuntary [See Necessity]; grudging, forced; irreconcilable.
   ADVERB:UNWILLINGLY &c. adj.; grudgingly, with a heavy heart; with -a bad, – an ill- grace; against -, sore against- -one’s wishes, – one’s will, – the grain; invita Minerva [L.]; à contre cœur [F.]; malgré soi [F.]; in spite of -one’s teeth, – oneself; nolens volens [L.] (necessity) [See Necessity]; perforce [See Compulsion]; under protest; no [See Negation]; if I must I must; not if one can help it; not for the world; far be it from me.