| critical(adjective, severe, important, significant, original) |
| chief(adjective, important, significant, essential, basic) |
| paramount(adjective, important, significant, original, essential) |
| core(noun, adjective, support, action, cause) |
| major(adjective, important, significant, original, essential) |
| leading(adjective, important, head, significant, beginning) |
| capital(adjective, important, essential, prime, vital) |
| dominant(adjective, top, important, significant, usual) |
| focal(adjective, important, significant, main) |
| nitty-gritty(noun, adjective, part, important, essential) |
| absolute(noun, adjective, rule, certain, essential) |
| meat-and-potatoes(adjective, important, original, essential, critical) |
| particular(noun, drop, part, material, essential) |
| quintessential(adjective, important, significant, essential, basic) |
| special(adjective, important, chief, foremost) |
| foremost(adjective, important, significant, original, essential) |
| heavy(important, essential, critical, basic) |
| life-or-death(important, essential, critical, basic) |
| nub(noun, adjective, cause, start, base) |
| substratal(adjective, clear, simple, plain, important) |