1. (

• guarantee ,
• ensure ,
• insure ,
• assure ,
• secure

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

2. (

• see ,
• check ,
• insure ,
• see_to_it ,
• ensure ,
• control ,
• ascertain ,
• assure

) 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" ;