| verb | make certain of “This nest egg will ensure a nice retirement for us” |
| verb | inform positively and with certainty and confidence “I tell you that man is a crook!” |
| verb | assure somebody of the truth of something with the intention of giving the listener confidence “I assured him that traveling to Cambodia was safe” |
| verb | be careful or certain to do something; make certain of something “He verified that the valves were closed” |
| verb | cause to feel sure; give reassurance to “The airline tried to reassure the customers that the planes were safe” |
| verb | make a promise or commitment |
| guarantee | noun | an unconditional commitment that something will happen or that something is true |
| assurance | noun | a statement intended to inspire confidence |
| check | noun | additional proof that something that was believed (some fact or hypothesis or theory) is correct |
| reassurance | noun | the act of reassuring; restoring someone's confidence |
| promissory | adjective | relating to or having the character of a promise |
| promiser | noun | a person who makes a promise |
| promise | noun | a verbal commitment by one person to another agreeing to do (or not to do) something in the future |
| promisee | noun | a person to whom a promise is made |
| promisor | noun | a person who makes a promise |