admonition

(noun) cautionary advice about something imminent (especially imminent danger or other unpleasantness). Synonyms: monition, warning, word of advice. Examples: "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."

(noun) a firm rebuke. Synonyms: admonishment, monition.