Emily Dickinson Lexicon

martyr (-s), n. [L. < Gk 'witness'.]

1. Sufferer for a cause; one who bears witness to truth by dying for it; person who gives up their life for a belief; someone who is killed for testifying of the gospel, such as Jesus Christ, Stephen, and other Christians (see Acts 6:8-8:1).
2. Phrase. “martyrs albums”: hagiography; [genitive] martyrs' albums; book about martyrs in the Protestant tradition (see John Foxe's 1543 Book of Martyrs); book about saints in the Catholic tradition; records about people who suffered death because of their faith.