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

602. Willingness.

   NOUN:WILLINGNESS, voluntariness &c. adj.; willing mind, heart.
  DISPOSITION, inclination, liking, turn, propensity, propension, propenseness, leaning, animus; frame of mind, humor, mood, vein; bent (turn of mind) [See Affections]; penchant [F.] (desire) [See Desire]; aptitude [See Skill].
  DOCILITY, docibleness [rare], docibility [rare], appetency, tractability, tractableness, persuadability, persuadableness, persuasibleness, persuasibility; pliability (softness) [See Softness].
  GENIALITY, cordiality; goodwill; alacrity, readiness, zeal, enthusiasm, earnestness, forwardness; eagerness (desire) [See Desire].
  ASSENT [See Assent]; compliance [See Consent]; pleasure (will) [See Will].
  LABOR OF LOVE, self-appointed task, volunteering; gratuitous service; social service, welfare work.
  VOLUNTEER, unpaid worker, amateur, voluntary [rare]; social worker, welfare worker.
   VERB:BE WILLING &c. adj.; incline, lean to, mind, propend [rare], had as lief, would as lief; lend -, give -, turn- a willing ear; have -a, – half a, – a great- mind to; hold to, cling to; desire [See Desire].
  ACQUIESCE (assent) [See Assent]; see -, think- -good, – fit, – proper; comply with [See Consent].
  swallow -, nibble at- the bait; swallow bait, hook, and sinker; swallow bait and all; gorge the hook; have -, make- no scruple of; make no bones of [colloq.]; jump at, catch at; go in for, go in at [both colloq.]; take up, plunge into, have a go at [colloq.]; meet halfway.
  VOLUNTEER, offer, proffer; offer oneself [See Offer].
   ADJECTIVE:WILLING, minded, fain, disposed, inclined, favorable; favorably -minded, -inclined, -disposed; well-disposed, lief [archaic], nothing loth; in the -vein, – mood, – humor, – mind.
  READY, forward, earnest, eager, zealous, enthusiastic; bent upon (desirous) [See Desire]; predisposed, desirous, propense.
  DOCILE; persuadable, persuasible; suasible, amenable, easily persuaded, facile, easy-going; tractable (pliant) [See Softness]; genial, gracious, cordial, cheering, hearty; content (assenting) [See Assent].
  VOLUNTARY, gratuitous, spontaneous; unasked &c. (ask [See Request]); unforced (free) [See Freedom].
   ADVERB:WILLINGLY &c. adj.; fain, freely, as lief, heart and soul; with pleasure, with all one’s heart, with open arms; with good will, with right good will; de bonne volonté [F.], ex animo [L.], con amore [It.], heart in hand, nothing loath, without reluctance, of one’s own accord, graciously, with a good grace; without demur.
  à la bonne heure [F.]; by all means, by all manner of means; to one’s heart’s content; yes (assent) [See Assent].
   INTERJECTION:SURELY! sure! with pleasure! of course! delighted!