ensure

(v) make certain of
- This nest egg will ensure a nice retirement for us
- Preparation will guarantee success!
assure, guarantee, insure, secure,
(v) 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
insure, see to it, ascertain, check, assure, control, see,

assure guarantee insure secure see to it ascertain check control see

ensue