assure
as-sure
verb
To state confidently to someone to remove doubt or anxiety.
"I assure you it will be fine."
verb
To guarantee or make something certain to occur.
"Hard work assures success in exams."
verb
To provide financial protection, especially for life.
"He assured his life for a million pounds."
Thesaurus
Synonyms: ascertain, ensure, control, see, insure, check, see to it, promise, tell, guarantee, secure