THESAURUS
Assure
afford hope, and candle, ascertain, assert, assert under oath, asseverate, attest, augur well, avouch, back, be convincing, be sponsor for, bear up, bid fair, bolster, bond, book, brace up, bring home to, bring over, bring round, bring to reason, buck up, carry conviction, certify, cheer, cinch, clear up, clinch, comfort, condole with, confirm, console, convert, convict, convince, countersecure, countersign, decide, depone, depose, determine, dismiss all doubt, drive home to, ease, embolden, encourage, endorse, ensure, establish, find out, fix, get at, give comfort, give hope, guarantee, guaranty, have good prospects, hearten, hold out hope, hold out promise, inspire, inspire belief, inspire hope, inspirit, insure, justify hope, kiss the book, lead to believe, make a promise, make certain, make fair promise, make no doubt, make no mistake, make sure, make sure of, nail down, nerve, persuade, pledge, plight, promise, put at ease, raise expectations, raise hope, reassure, relieve, remove all doubt, satisfy, secure, see that, see to it, sell, sell one on, set at ease, set at rest, settle, sign, sign for, solace, sort out, sponsor, stabilize, stand behind, stand up for, state, subscribe to, support, swear, swear by bell, swear the truth, swear to, swear to God, swear to goodness, sympathize with, talk over, testify, troth, undersign, underwrite, vouch, vow, warrant, win over
ROGET THESAURUS
Assure
Promise
VB
promise, give a promise, undertake, engage, make an engagement, form an engagement, enter into an engagement, enter on an engagement, bind oneself, tie oneself, pledge oneself, commit oneself, take upon oneself, vow, swear, give one's word, pass one's word, pledge one's word, plight one's word, give one's honor, pass one's honor, pledge one's honor, plight one's honor, give credit, pass credit, pledge credit, plight credit, give troth, pass troth, pledge troth, plight troth, betroth, plight faith, assure, warrant, guarantee, covenant, attest, hold out an expectation, contract an obligation, become bound to, become sponsor for, answer for, be answerable for, secure, give security, underwrite, adjure, administer an oath, put to one's oath, swear a witness.
Security
VB
give security, give bail, give substantial bail, go bail, pawn, impawn, spout, mortgage, hypothecate, impignorate, guarantee, warrant, warrantee, assure, accept, indorse, underwrite, insure, cosign, countersign, sponsor, cosponsor, execute, stamp, sign, seal, let, sett, grant a lease, take a lease, hold a lease, hold in pledge, lend on security.
Hope
VB
hope, trust, confide, rely on, put one's trust in, lean upon, pin one's hope upon, pin one's faith upon, feel hope, entertain hope, harbor hope, indulge hope, cherish hope, feed hope, foster hope, nourish hope, encourage hope, cling to hope, live in hope see land, feel assured, rest assured, feel confident, rest confident, presume, promise oneself, expect, hope for, anticipate, be hopeful, look on the bright side of, view on the sunny side, voir en couleur de rose, make the best of it, hope for the best, put a good face upon, put a bold face upon, put the best face upon, keep one's spirits up, take heart, take heart of grace, be of good heart, be of good cheer, flatter oneself, lay the flattering unction to one's soul, catch at a straw hope against hope, reckon one's chickens before they are hatched, count one's chickens before they are hatched, give hope, inspire hope, raise hope, hold out hope, promise, bid fair, augur well, be in a fair way, look up, flatter, tell a flattering tale, raise expectations (sentient subject), encourage, cheer, assure, reassure, buoy up, embolden.
Certainty
VB
be certain, stand to reason, render certain, insure, ensure, assure, clinch, make sure, determine, decide, set at rest, make assurance double sure, know, dogmatize, lay down the law.
Belief
VB
believe, credit, give faith to, give credit to, credence to, see, realize, assume, receive, set down for, take for, have it, take it, consider, esteem, presume, count upon, depend upon, calculate upon, pin one's faith upon, reckon upon, lean upon, build upon, rely upon, rest upon, lay one's account for, make sure of, make oneself easy about, on that score, take on trust, take on credit, take for granted, take for gospel, allow some weight to, attach some weight to, know, know for certain, have know, make no doubt, doubt not, be, rest assured, persuade oneself, assure oneself, satisfy oneself, make up one's mind, give one credit for, confide in, believe in, put one's trust in, place in, repose in, implicit confidence in, take one's word for, at one's word, place reliance on, rely upon, swear by, regard to, think, hold, take, take it, opine, be of opinion, conceive, trow, ween, fancy, apprehend, have it, hold a belief, possess, entertain a belief, adopt a belief, imbibe a belief, embrace a belief, get hold of a belief, hazard, foster, nurture a belief, cherish a belief, have an opinion, hold an opinion, possess, entertain an opinion, adopt an opinion, imbibe an opinion, embrace an opinion, get hold of an opinion, hazard an opinion, foster an opinion, nurture an opinion, cherish an opinion, view as, consider as, take as, hold as, conceive as, regard as, esteem as, deem as, look upon as, account as, set down as, surmise, get it into one's head, take it into one's head, come round to an opinion, swallow, cause to be believed, satisfy, persuade, have the ear of, gain the confidence of, assure, convince, convict, convert, wean, bring round, bring over, win over, indoctrinate, cram down the throat, produce conviction, carry conviction, bring home to, drive home to, go down, find credence, pass current, be received, be current, possess, take hold of, take possession of the mind.
Affirmation
VB
assert, make an assertion, have one's say, say, affirm, predicate, declare, state, protest, profess, put forth, put forward, advance, allege, propose, propound, enunciate, broach, set forth, hold out, maintain, contend, pronounce, pretend, depose, depone, aver, avow, avouch, asseverate, swear, make oath, take one's oath, make an affidavit, swear an affidavit, put in an affidavit, take one's Bible oath, kiss the book, vow, vitam impendere vero, swear till one is black in the face, swear till one is blue in the face, swear till all's blue, be sworn, call Heaven to witness, vouch, warrant, certify, assure, swear by bell book and candle, swear by, insist upon, take one's stand upon, emphasize, lay stress on, assert roundly, assert positively, lay down, lay down the law, raise one's voice, dogmatize, have the last word, rap out, repeat, reassert, reaffirm, announce, acknowledge, attest, adjure.