warning
noun
a message informing of danger
“a warning that still more bombs could explode”
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”
notification of something, usually in advance
“they gave little warning of their arrival”
“she had only had four days' warning before leaving Berlin”
adjective
serving to warn
“shook a monitory finger at him”
“an exemplary jail sentence”
Source: WordNet 3.1, Princeton University