- accountable, insignificant, voluntary, unnecessary, docile, constitutional, ductile, discretionary, chosen, inessential, compliant, limited, free, unimportant, meek, complaisant, lowly, mild, inconsequential, unwanted, submissive, responsible, lenient, contingent, conditional, gentle, discretional, liberated, unneeded, humble, unstipulated, optional, nonessential, Liberalized, dispensable, yielding.
It's not compulsory, you know. "Pygmalion" by George Bernard Shaw
Their intentions uniformly tended to vice, and no good was to be expected from them, except such as was the effect of compulsory measures; so that the task which industry might have achieved with comparative ease, proved, under existing circumstances, a work of difficulty, requiring time and perseverance to bring it to the desired perfection. "The Present Picture of New South Wales (1811)" by David Dickinson Mann
The Indians, when they recognised him, completely forgot the orders they had received from their Spanish masters, and in mingled joy at seeing their beloved Bishop again and distress at being there under such duty, they threw themselves at his feet, weeping, protesting, and imploring his forgiveness for their compulsory part in opposing him. "Bartholomew de Las Casas; his life, apostolate, and writings" by Francis Augustus MacNutt