alert-n; 3 Senses

Sense Number 1: condition of watchfulness.

Examples:
Bombers were put on alert to danger.
We were all on alert that evening.

Mappings:
PropBank: NP
WordNet 3.0 Sense Numbers: 1

Sense Number 2: warning or admonition

Commentary: ALERT[+event]
NOTE: Warning is NOT automatic signal.

Examples:
She gave me a verbal alert.
Many alerts came in of fire danger.

Mappings:
PropBank: NP
WordNet 3.0 Sense Numbers: 2

Sense Number 3: warning, typically a siren.

Commentary: ALERT[+event]

Examples:
The alarms provided us all with an alert.
The house alarm gives adequate alert of intruders.

Mappings:
PropBank: NP
WordNet 3.0 Sense Numbers: 3