a person who is put to death because of their religious beliefs

any person who suffers for any cause or set of beliefs

the Tolpuddle martyrs

a victim of constant suffering

a martyr to migraine

a person who behaves unnecessarily, even pointedly, in a self-sacrificing manner

OK, be a martyr if you must

to put (somebody) to death as a martyr

to inflict agonizing pain on (somebody)

racked with sciatics, martyred with the stone — Pope