| compulsory(adjective, set, significant, affected, essential) |
| required(adjective, right, significant, essential, basic) |
| obligatory(adjective, right, significant, affected, essential) |
| necessary(adjective, right, essential, obvious, obligation) |
| imperative(adjective, set, significant, essential, basic) |
| requisite(adjective, significant, essential, basic, vital) |
| indispensable(adjective, set, significant, essential, basic) |
| essential(adjective, set, significant, basic, vital) |
| binding(adjective, set, significant, affected, essential) |
| forced(adjective, affected, necessary, strained, unnatural) |
| involuntary(adjective, affected, necessary, strained, unnatural) |
| imperious(adjective, necessary, commanding, required, authoritative) |
| inevitable(adjective, obvious, required, obligatory, inescapable) |
| mandate |
| needed(adjective, set, significant, essential, basic) |
| commanding(adjective, necessary, required) |
| mandatary |
| prerequisite(adjective, set, significant, essential, basic) |
| de rigueur(expression, adjective, idiom, right, significant) |
| authoritative(adjective, official, authorized) |