| critical(adjective, important, original, essential, basic) |
| de rigueur(expression, adjective, significant, essential, basic) |
| decisive(adjective, important, significant, essential, critical) |
| elemental(adjective, important, significant, original, essential) |
| elementary(adjective, important, significant, original, essential) |
| essential(adjective, important, significant, original, critical) |
| exigent(adjective, significant, essential, basic, vital) |
| expedient(adjective, significant, essential, basic, vital) |
| first(adjective, important, significant, original, basic) |
| foundational(adjective, important, significant, original, essential) |
| grass-roots(adjective, important, significant, original, essential) |
| heavy(adjective, important, essential, critical, basic) |
| imperative(adjective, important, significant, essential, critical) |
| incumbent on(expression, adjective, significant, essential, basic) |
| intrinsic(adjective, important, significant, original, essential) |
| key(adjective, important, original, essential, critical) |
| life-or-death(adjective, important, essential, critical, basic) |
| major(adjective, important, significant, original, basic) |
| meaningful(adjective, important, essential, critical, fundamental) |
| name(adjective, important, essential, critical, basic) |