| prerequisite(noun, condition, want, need, essential) |
| sine qua non(noun, expression, idiom, condition, need) |
| affair(noun, activity, business, action, work) |
| arrears(noun, damage, condition, pay, balance) |
| cause(noun, reason, need, responsibility, essential) |
| coercion(noun, trouble, force, drive, power) |
| due(noun, damage, burden, pay, balance) |
| force(noun, trouble, power, strength, energy) |
| inevitability(noun, need, essential, requirement, prerequisite) |
| inexorability(noun, requirement) |
| loyalty(noun, burden, responsibility, liability, onus) |
| mission(noun, business, action, work, charge) |
| occupation(noun, business, place, work, charge) |
| ought(noun, verb, work, charge, right) |
| restraint(noun, charge, concern, burden, authority) |
| right(noun, cause, concern, reason, care) |
| role(noun, action, place, work, charge) |
| stint(noun, activity, performance, action, work) |
| strain(noun, trouble, force, power, strength) |
| thankfulness(noun, appreciation, recognition, thanks, gratitude) |