| fundamental(adjective, important, significant, original, essential) |
| cardinal(adjective, important, significant, original, essential) |
| crucial(adjective, important, significant, original, essential) |
| indispensable(adjective, important, significant, original, essential) |
| integral(adjective, important, significant, original, essential) |
| meat-and-potatoes(adjective, important, significant, original, essential) |
| necessary(adjective, important, significant, original, essential) |
| requisite(adjective, important, significant, original, essential) |
| all-important(adjective, significant, essential, basic, vital) |
| axiological(adjective, important, significant, original, essential) |
| axiomatic(adjective, important, significant, original, basic) |
| basal(adjective, important, significant, original, essential) |
| basic(adjective, important, significant, original, essential) |
| bottom(adjective, important, significant, original, essential) |
| central(adjective, important, significant, original, basic) |
| chief(adjective, significant, essential, basic, vital) |
| coal-and-ice(adjective, important, essential, critical, basic) |
| compelling(adjective, significant, essential, basic, vital) |
| constitutional(adjective, important, significant, original, basic) |
| constitutive(adjective, important, significant, essential, critical) |