| fundamental(adjective, important, essential, critical, basic) |
| basic(adjective, important, essential, critical, fundamental) |
| necessary(adjective, important, essential, critical, basic) |
| bottom-line(adjective, important, essential, critical, basic) |
| cardinal(adjective, important, essential, critical, basic) |
| coal-and-ice(adjective, important, significant, essential, critical) |
| constitutive(adjective, important, essential, critical, basic) |
| decisive(adjective, important, essential, critical, basic) |
| heavy(adjective, important, significant, essential, critical) |
| integral(adjective, important, essential, critical, basic) |
| meat-and-potatoes(adjective, important, significant, essential, critical) |
| name(adjective, important, significant, essential, critical) |
| name-of-the-game(adjective, important, significant, essential, critical) |
| needed(adjective, important, essential, critical, basic) |
| nitty-gritty(adjective, important, essential, critical, basic) |
| prerequisite(adjective, important, essential, critical, basic) |
| required(adjective, important, essential, critical, basic) |
| requisite(adjective, important, essential, critical, basic) |
| underlined(adjective, important, significant, essential, critical) |