adj. 25B6; adjective
it is vital that action is taken : ESSENTIAL, of the essence, critical, crucial, indispensable, all-important, imperative, mandatory, urgent, pressing, burning, compelling, high-priority; informal earth-shattering, world-shaking.
the vital organs : MAJOR, main, chief; essential, necessary.
he is young and vital : LIVELY, energetic, active, sprightly, spry, spirited, vivacious, exuberant, bouncy, enthusiastic, vibrant, zestful, sparkling, dynamic, vigorous, lusty, hale and hearty; informal peppy, spunky, full of beans, bright-eyed and bushy-tailed.
unimportant, minor, listless.