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

Class V. Words Releasing to the Voluntary Powers
Division (II) Intersocial Volition
Section III. Conditional Intersocial Volition

768. Promise.

   NOUN:PROMISE, under-taking, word, troth, plight, pledge, parole, word of honor, vow; oath (affirmation) [See Affirmation]; profession, assurance, warranty, guarantee, insurance, obligation; contract [See Compact]; stipulation.
  ENGAGEMENT, preëngagement; affiance; betrothal, betrothment; marriage -contract, – vow; plighted faith, troth-plight [Scot. or dial.], gage d’amour [F.].
   VERB:PROMISE; give a promise &c. n.; undertake, engage; make -, form- an engagement; enter into or on an engagement; bind -, tie -, pledge -, commit -, take upon- oneself; vow; swear (affirm) [See Affirmation], give -, pass -, pledge -, plight- one’s -word, – honor, – credit, – troth; betroth, plight faith, take the vows, trothplight [Scot. or dial.].
  ASSURE, warrant, guarantee; covenant [See Compact]; avouch, vouch for; attest (bear witness) [See Evidence].
  hold out an expectation; contract an obligation; become bound to, become sponsor for; answer for, be answerable for; secure; give security [See Security]; underwrite.
  ADJURE, administer an oath, put to one’s oath, swear a witness.
   ADJECTIVE:PROMISING &c. v.; promissory; votive; under hand and seal, upon oath, upon the Book; upon -, on- affirmation.
  PROMISED &c. v.; affianced, pledged, bound; committed, compromised; in for it [colloq.].
   ADVERB:as true as I live; in all soberness; upon my honor; my word for it; my head upon it; I call God to witness; as one’s head shall answer for; ex voto [L.].
  1. His word is his bond.
  2. In for a penny in for a pound.
  3. Indeed, indeed, Repentance oft before I swore—but, was I sober when I swore?—Omar Khayyám—Fitzgerald
  4. Thy promises are like Adonis’ gardens, That one day bloom’d, and fruitful were the next.—I Henry VI