assure in WordNet English dictionary

1. 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"
   see  check  insure  see to it  ensure  control  ascertain  assure 
   
2. inform positively and with certainty and confidence
   "I tell you that man is a crook!"
   assure  tell 
   
3. assure somebody of the truth of something with the intention of giving the listener confidence
   "I assured him that traveling to Cambodia was safe"
   assure 
   
4. make a promise or commitment
   promise  assure 
   
5. make certain of
   "This nest egg will ensure a nice retirement for us"; "Preparation will guarantee success!"
   guarantee  ensure  insure  assure  secure 
   
6. cause to feel sure; give reassurance to
   "The airline tried to reassure the customers that the planes were safe"
   reassure  assure