To sever or cut off something physically or to break a connection or relationship.
彼はその会社との関係を断った。
He severed ties with that company.
台風で橋が壊れ、道路が断たれた。
The bridge was destroyed by the typhoon and the road was cut off.
工事で電気の供給を一時的に断つ。
They temporarily cut off the power supply for construction work.
To suppress, eradicate, or eliminate something harmful (e.g., bad habits, infections, crime).
悪習を断つために教育プログラムを導入した。
They introduced an educational program to eradicate bad practices.
感染経路を断つことが流行を抑える鍵だ。
Cutting off the routes of infection is the key to controlling an outbreak.
犯罪の連鎖を断つために警察は重点取締りを行った。
The police carried out targeted crackdowns to break the chain of crime.
To abstain from or give up something (e.g., drinking, smoking).
医者の勧めで彼は酒を断った。
On his doctor's advice, he gave up drinking.
新年にタバコを断つと決めた。
He decided to stop smoking for the new year.
試験勉強の間は外出を断ち、家で集中した。
During exam study time he refrained from going out and concentrated at home.