What is the X in X-mas?
c.1300, "to pierce, penetrate," metathesis of Old English þyrlian, from þyrel "hole" (in Middle English, also "nostril"), from þurh "through" (cf. Middle High German dürchel "pierced, perforated;" see through) + -el. Meaning "give a shivering, exciting feeling" is first recorded 1590s, via metaphoric notion of "pierce with emotion." Related: Thrilled; thrilling.
"a shivering, exciting feeling," 1670s, from thrill (v.). Meaning "a thrilling experience" is attested from 1936.
The vibration accompanying a cardiac or vascular murmur, detectible on palpation.