| necessary(adjective, right, important, essential, critical) |
| needed(verb, adjective, close, correct, exact) |
| essential(adjective, important, significant, critical, basic) |
| compulsory(adjective, significant, essential, basic, vital) |
| requisite(adjective, close, correct, exact, important) |
| indispensable(adjective, important, significant, serious, essential) |
| obligatory(adjective, right, significant, essential, basic) |
| imperative(adjective, important, significant, essential, critical) |
| mandatory(adjective, right, significant, essential, basic) |
| needful(adjective, important, significant, capital, essential) |
| vital(adjective, important, significant, serious, essential) |
| asked |
| desired(verb, adjective, necessary, wanted, needed) |
| wanted(verb, adjective, important, significant, serious) |
| demanded(verb, adjective, obliged) |
| obliged(verb, obliged) |
| prerequisite(adjective, important, significant, essential, critical) |
| binding(adjective, significant, essential, basic, vital) |
| bound(verb, adjective, destined, obligated) |
| compelled |