admonition

Noun

• a firm rebuke

• cautionary advice about something imminent (especially imminent danger or other unpleasantness)
  • a letter of admonition about the dangers of immorality
    
  • the warning was to beware of surprises
    
  • his final word of advice was not to play with matches
    

Related words

• Synonyms: 
  admonishment , monition , warning , word of advice