What is the X in X-mas?
c.1400, from escape (v.); earlier eschap (c.1300). Mental/emotional sense is from 1853. Escape clause in the legal sense first recorded 1945.
escape es·cape (ĭ-skāp')
A gradual effusion from an enclosure; a leakage.
A cardiological situation in which one pacemaker defaults or an atrioventricular conduction fails, and another pacemaker sets the heart's pace for one or more beats.
An early system on the IBM 650.
[Listed in CACM 2(5):16 (May 1959)].