Martyr (noun)

1. A person who suffers death or persecution for their religious or other beliefs.
2. A person who makes great sacrifices or suffers much in order to further a belief or cause.
3. A person who is put to death or endures great suffering on behalf of any belief, principle, or cause.

Origin:

Middle english: via old french from latin martyr, from greek martys "witness".

Examples:

1. The martyr died for her religious beliefs.
2. He became a martyr for the civil rights movement.
3. The martyrs of the revolution were remembered in a ceremony.
4. The martyr's sacrifice inspired others to join the cause.
5. The martyr's death was not in vain.