na-adjective
Describes something related to morality or ethics, often used in formal or philosophical contexts.
彼の行動は道義的に許されない。
His actions are morally unacceptable.
道義的な責任を感じる。
I feel a moral responsibility.
Compound of 道義 (morality, moral principles) + 的 (-like, -ical). The exact historical derivation is uncertain, but the word follows a common pattern for forming adjectival nouns from Sino-Japanese nouns.