even at the cost of one's life; with one's life
Fixed expression used to emphasize that one will protect or defend something no matter what, even if it means risking death. Often followed by verbs like 守る or 護る.
I will protect this secret even at the cost of my life.
I am prepared to protect my family with my life.
Kana variant of 代え; common in everyday writing.
A fixed phrase composed of 命 (life), に (particle), 代えて (te-form of 代える, 'to substitute'), and も ('even'). Literally 'even substituting one's life', it has become a set expression meaning 'even at the cost of one's life'.