| leading(adjective, feature, state, characteristic, importance) |
| must(noun, adjective, right, want, need) |
| needed(adjective, set, important, significant, capital) |
| real(adjective, material, natural, basic, genuine) |
| ingrained(adjective, characteristic, natural, individual, basic) |
| radical(adjective, importance, important, significant, original) |
| sine qua non(noun, expression, idiom, condition, importance) |
| element(noun, form, drop, part, fix) |
| focal(adjective, important, significant, main, private) |
| grave(adjective, severe, importance, big, important) |
| mandatory(adjective, set, significant, basic, vital) |
| meaningful(adjective, importance, big, important, significant) |
| needful(adjective, set, important, significant, original) |
| obligatory(adjective, important, significant, critical, basic) |
| responsible(adjective, importance, valuable, duty, reliable) |
| serious(adjective, severe, importance, big, important) |
| weighty(adjective, importance, big, important, significant) |
| consequential(adjective, importance, big, important, significant) |
| first(adjective, important, significant, original, prominent) |
| gut(adjective, individual, intimate, secret, private) |