expression, godan verb (-tsu)
to fast; to abstain from eating
A somewhat formal or literary expression for fasting, often implying a deliberate, sometimes spiritual or protest-related, abstention from food.
彼は宗教的な理由で三日間食を断った。
He fasted for three days for religious reasons.
ハンガーストライキで
The prisoners are fasting as part of a hunger strike.