Define the following words: Critical, Emergency, Unconscious, Security, Ambulance, Rescue.

Here are the meanings of the words:

a) Critical: Extremely important or serious, or at a point of crisis.

b) Emergency: A serious, unexpected, and often dangerous situation requiring immediate action.

c) Unconscious: Not awake and aware of one's surroundings, typically as a result of injury or illness.

d) Security: The state of being free from danger or threat.

e) Ambulance: A vehicle specially equipped for taking sick or injured people to and from a hospital.

f) Rescue: To save someone or something from a dangerous or difficult situation.