| essential(adjective, importance, valuable, basic, fundamental) |
| central(adjective, lead, important, head, master) |
| vital(adjective, importance, important, valuable, essential) |
| principal(adjective, lead, important, head, significant) |
| important(adjective, importance, valuable, main, notable) |
| solution(noun, answer, resolution, return, sign) |
| fundamental(noun, adjective, important, head, significant) |
| main(adjective, lead, important, head, significant) |
| cardinal(noun, adjective, lead, important, head) |
| chief(adjective, lead, important, head, significant) |
| primary(adjective, lead, important, head, significant) |
| crucial(adjective, important, significant, original, essential) |
| substantial(adjective, importance, important, valuable, main) |
| core(noun, adjective, lead, importance, head) |
| grand(adjective, lead, importance, head, master) |
| major(adjective, lead, important, head, significant) |
| material(adjective, importance, important, significant, large) |
| prime(adjective, lead, important, head, significant) |
| serious(adjective, importance, important, valuable, main) |
| weighty(adjective, importance, important, valuable, main) |