| vital(adjective, body, severe, importance, material) |
| fundamental(noun, adjective, support, action, characteristic) |
| basic(noun, adjective, characteristic, drop, part) |
| necessary(noun, adjective, body, material, big) |
| important(adjective, severe, importance, big, significant) |
| primary(adjective, body, simple, plain, importance) |
| intrinsic(adjective, characteristic, physical, material, important) |
| requisite(noun, adjective, right, condition, important) |
| crucial(adjective, severe, big, important, significant) |
| indispensable(adjective, characteristic, important, significant, original) |
| key(adjective, importance, valuable, basic, fundamental) |
| inherent(adjective, characteristic, body, reasonable, material) |
| main(adjective, importance, important, significant, basic) |
| principal(adjective, body, importance, material, big) |
| imperative(noun, adjective, form, fix, pass) |
| required(adjective, important, significant, capital, critical) |
| elementary(adjective, characteristic, simple, plain, pure) |
| organic(adjective, important, significant, natural, animate) |
| elemental(adjective, characteristic, body, simple, plain) |
| prime(adjective, body, importance, material, pure) |