Both Uses

martyr
in
Henry IV, Part 2
(Auto-generated)

Yea, but our valuation shall be such That every slight and false-derived cause, Yea, every idle, nice and wanton reason Shall to the king taste of this action; That, were our royal faiths martyrs in love, We shall be winnow'd with so rough a wind That even our corn shall seem as light as chaff And good from bad find no partition.†
Scene 4.1 *

martyrs = dies or suffers due to upholding principle; or people who have suffered such a fate
If you be not too much cloy'd with fat meat, our humble author will continue the story, with Sir John in it, and make you merry with fair Katharine of France: where, for any thing I know, Falstaff shall die of a sweat, unless already a' be killed with your hard opinions; for Oldcastle died a martyr, and this is not the man.†
Scene 5.5

martyr = someone who dies or suffers to uphold principles

Definitions:

(1) (martyr)
someone who is killed or made to suffer greatly for their beliefs, often unjustly; or someone who acts as if they suffer a lot; or to make someone into such a person
(2) (meaning too rare to warrant focus)