| sine qua non(noun, expression, idiom, condition, need) |
| basic(noun, adjective, important, want, significant) |
| stipulation(noun, condition, essential, requirement, qualification) |
| crucial(adjective, important, significant, original, essential) |
| obligation(noun, right, want, need, essential) |
| demanded |
| desideratum(noun, right, want, need, essential) |
| important(adjective, significant, original, essential, critical) |
| precondition(noun, condition, need, essential, certainty) |
| provision(noun, condition, essential, requirement, qualification) |
| binding(adjective, significant, essential, basic, vital) |
| critical(adjective, important, essential, basic, fundamental) |
| happy |
| integral(adjective, important, significant, original, essential) |
| pressing(adjective, significant, essential, basic, vital) |
| right(noun, adjective, correct, fit, appropriate) |
| constraint(noun, obligation, requirement) |
| due(adjective, good, correct, right, reasonable) |
| essence(condition, need, essential, basic, requirement) |
| inevitable(adjective, required, obligatory) |