na-adjective, noun
level emotion; frankness; open-heartedness
Rare literary word describing a calm, open, and unguarded emotional state. Not used in everyday conversation; found mainly in older or formal writing.
彼の坦懐な態度に、周囲の人々は心を開いた。
His open-hearted attitude made those around him open up.
この文章では「坦懐」という古い表現が使われている。
In this text, the old expression '坦懐' is used.
坦懐 is a Sino-Japanese compound (kango) combining 坦 (level, flat, calm) and 懐 (heart, feelings). The exact historical derivation is uncertain, but it follows a classical pattern of forming abstract nouns and adjectives from kanji with related meanings.