Main entry: control, assure, ascertain, insure, check, ensure, see, see to it
Definition: be careful or certain to do something; make certain of something
Usage: He verified that the valves were closed; See that the curtains are closed; control the quality of the product
Main entry: assure, secure, guarantee, insure, ensure
Definition: make certain of
Usage: This nest egg will ensure a nice retirement for us; Preparation will guarantee success!