adjective
1.
Synonyms: living 1, alive, animate, animated, zoetic
Related Word: breathing
2.
Synonyms: vigorous , dynamic, energetic, lusty, red-blooded, strenuous, ||survigrous
3.
Synonyms: essential 2, cardinal, constitutive, fundamental
Related Word: indispensable, needed, needful, required, requisite; integral, prerequisite