verb (v)

• establish after a calculation, investigation, experiment, survey, or study(verb.communication)

  Synonym:
  determine, find, find out
  

  source: wordnet30
• be careful or certain to do something; make certain of something(verb.cognition)

  Synonym:
  assure, check, control, ensure, insure, see, see to it
  

  source: wordnet30
• find out, learn, or determine with certainty, usually by making an inquiry or other effort(verb.communication)

  Synonym:
  check, determine, find out, learn, see, watch
  

  source: wordnet30
• learn or discover with certainty(verb.cognition)

  source: wordnet30
• To render (a person) certain; to cause to feel certain; to make confident; to assure; to apprise.(verb)

  source: webster1913