| inherent(adjective, characteristic, close, start, natural) |
| innate(adjective, characteristic, start, natural, fixed) |
| essential(adjective, characteristic, physical, material, important) |
| inborn(adjective, characteristic, start, natural, fixed) |
| congenital(adjective, characteristic, start, natural, fixed) |
| inbred(adjective, characteristic, start, natural, fixed) |
| deep-seated(adjective, characteristic, natural, original, fixed) |
| constitutional(adjective, characteristic, close, start, important) |
| fundamental(adjective, characteristic, important, significant, natural) |
| elemental(adjective, characteristic, start, important, significant) |
| basic(adjective, characteristic, important, significant, natural) |
| underlying(adjective, important, significant, original, essential) |
| radical(adjective, important, significant, original, essential) |
| connate(adjective, characteristic, natural, essential, basic) |
| material(noun, adjective, solid, physical, important) |
| elementary(adjective, characteristic, important, significant, natural) |
| primary(adjective, important, significant, original, essential) |
| absolute(adjective, physical, material, true, basic) |
| cardinal(adjective, important, significant, original, essential) |
| indispensable(adjective, characteristic, important, significant, natural) |