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"
- see to it
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!"