プログレッシブ和英中辞典(第4版)の解説
ちんちゃく【沈着】
self-possession; composure
沈着な composed; calm
沈着な面持ち
a collected look
彼は沈着な態度を失わなかった
He never lost his poise [presence of mind].／He remained unperturbed [calm].
彼は沈着に行動した
He acted with composure [self-possession].
地震の際は沈着であることが肝心だ
When an earthquake occurs, the important thing is to 「keep your head [《口》 keep cool].