war-n; 4 Senses

Sense Number 1: fighting, combat, armed conflict between social groups

Commentary:WAR[+event][+conflict][+armed][+between_groups][+social]

Examples:
Thousands of people were killed in the war.
They are concerned about the threat of a nuclear war.
The gang wars that erupted in the city last month were related to drug trafficking.
Their country is on the verge of a civil war.
The general discussed the unique challenges of waging war against terrorists.

Mappings:
PropBank: war.01
WordNet 3.0 Sense Numbers: 1

Sense Number 2: an official state of hostility declared by a sovereign nation

Commentary:WAR[+state][+declared][+officially][+of_hostility][+by_nation]
NOTE: the state of declaring hostility need not coincide with the onset of actual events of armed conflict.

Examples:
War was declared in November but actual fighting did not begin until the following spring.
The treaty prohibits any member nation from declaring war on any other member nation.

Mappings:
PropBank: war.01
WordNet 3.0 Sense Numbers: 2

Sense Number 3: a contentious competition to gain a goal

Commentary:WAR[+event_set][+competition][+contentious][+to_gain][+goal]

Examples:
This game is a war of wits that is fun for the whole family.
The protectionist bill passed in congress may start a trade war.
Consumer electronics have been marked down because of the price war going on between the discount chains.
The town is growing weary of the war of words between the mayor and the town councilor.

Mappings:
PropBank: NM
WordNet 3.0 Sense Numbers: 3

Sense Number 4: an official campaign against a perceived societal harm

Commentary:WAR[+event_set][+campaign][+official][+against][+societal_harm][+perceived]

Examples:
President Johnson is remembered for his large-scale war on poverty.
Skeptics argue that the war on drugs has largely failed to reach any of its goals.
The new homeland security measures are one component of the war on terrorism. (Note: in this context, no actual combat is referenced, it's a campaign to prevent certain acts from occurring.)
Mary has waged a one-woman war on litterbugs in her town.

Mappings:
PropBank: war.01
WordNet 3.0 Sense Numbers: 4