Meaning of the word "all is fair in love and war" in English

What does "all is fair in love and war" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

all is fair in love and war

US /ɔːl ɪz fer ɪn lʌv ænd wɔːr/
UK /ɔːl ɪz feər ɪn lʌv ənd wɔː/
"all is fair in love and war" picture

Idiom

used to justify behavior that would normally be considered unfair or unacceptable because the situation is so intense or important

Example:
He cheated to win her heart, but all is fair in love and war.
I didn't tell him about the job opening so I could apply first; all is fair in love and war.