assure

Verb

• make a promise or commitment

• cause to feel sure; give reassurance to
  • The airline tried to reassure the customers that the planes were safe
    

• be careful or certain to do something; make certain of something
  • He verified that the valves were closed
    
  • See that the curtains are closed
    
  • control the quality of the product
    

• assure somebody of the truth of something with the intention of giving the listener confidence
  • I assured him that traveling to Cambodia was safe
    

• inform positively and with certainty and confidence
  • I tell you that man is a crook!
    

• make certain of
  • This nest egg will ensure a nice retirement for us
    
  • Preparation will guarantee success!
    

Related words

• Synonyms: 
  promise , reassure , see , check , insure , see to it , ensure , control , ascertain , tell , guarantee , secure
• Antonyms: 
  worry , vex