unpostponable

verb (used with object), post·poned, post·pon·ing.

1. to put off to a later time; defer: He has postponed his departure until tomorrow.
2. to place after in order of importance or estimation; subordinate: to postpone private ambitions to the public welfare.

verb (tr)

1. to put off or delay until a future time
2. to put behind in order of importance; defer

v.c.1500, from Latin postponere “put after; esteem less; neglect; postpone,” from post “after” (see post-) + ponere “put, place” (see position (n.)). Related: Postponed; postponing.