Definition:
Death, die, and dead are all related to the end of life, but they have slightly different meanings.

Death: Death refers to the permanent cessation of all vital functions in a living organism. It is the state of being dead.

Die: Die is a verb that means to cease living or to expire. It is the act of transitioning from a living state to a dead state.

Dead: Dead is an adjective that describes something or someone that is no longer alive. It is the state of not being alive or living.

Differences:

1. Part of Speech:
- Death is a noun.
- Die is a verb.
- Dead is an adjective.

2. Usage:
- Death is used to refer to the state or concept of being dead.
- Die is used to describe the act of transitioning from life to death.
- Dead is used to describe something or someone that is already in the state of being dead.

Example Sentences:

- Death:
- "The death of a loved one is a difficult experience."
- "The doctor pronounced him dead."

- Die:
- "Many soldiers died in the battle."
- "The flowers will die if not watered regularly."

- Dead:
- "The bird lying on the ground is dead."
- "The phone battery is dead and needs to be charged."

Summary:
- Death is a noun that refers to the state of being dead.
- Die is a verb that describes the act of transitioning from life to death.
- Dead is an adjective used to describe something or someone that is no longer alive.