means A person who suffers or dies for a cause or belief, or — more loosely — someone who endlessly advertises their own sacrifice and suffering.

from From Greek 'martyr,' meaning simply 'witness' — someone who gave testimony. Early Christians adopted the word for those who bore witness to their faith with their lives, and the legal sense of 'one who testifies' hardened into 'one who dies for what they testify to.' Passed through Latin 'martyr' and into Old English, it kept that weight ever since — though the modern eye-rolling sense, the suffering-out-loud kind, is a much later softening.