Morally binding or necessary.

Roget 926: obligatory, binding; imperative, peremptory; stringent etc. (severe) 739; behooving etc. v.; incumbent on, chargeable on; under obligation; obliged by, bound by, tied by; saddled with.    due to, beholden to, bound to, indebted to; tied down; compromised etc. (promised) 768; in duty bound.    amenable, liable, accountable, responsible, answerable.    right, meet etc. (due) 924; moral, ethical, casuistical, conscientious, ethological.    ... meer laten zien