| befitting(good, correct, fit, appropriate, fair) |
| bottom(adjective, important, significant, original, essential) |
| boundary condition |
| call(verb, need, essential, requirement, prerequisite) |
| call for |
| called-for |
| catch |
| cause(need, essential, requirement, prerequisite, essentiality) |
| claim(noun, need, essential, requirement, prerequisite) |
| coal-and-ice(important, essential, critical, basic, fundamental) |
| commodious(good, fit, appropriate, acceptable, apposite) |
| constitutional(adjective, important, significant, original, essential) |
| constitutive(important, significant, capital, essential, critical) |
| contingency(condition, essential, requirement, qualification, prerequisite) |
| convenient(fit, appropriate, apposite) |
| copacetic(good, fit, appropriate, acceptable, apposite) |
| correct(good, fit, appropriate, fair, proper) |
| cut out for(expression, good, fit, appropriate, acceptable) |
| decisive(adjective, important, significant, essential, critical) |
| demand for |