The phrase let bygones be bygones is an old one, the earliest citation found is from the 1500s. We will examine the meaning of the term let bygones be bygones, where it came from and some examples of its use in sentences.
Let bygones be bygones is an admonition to put our differences behind us, to leave our disagreements in the past and go forward in friendship and cooperation. Bygones is the plural form of the word bygone, and is rarely used outside of the phrase let bygones be bygones. For this reason, bygones is considered a fossil word, for it does not exist outside of the idiom in which it is preserved. Bygone refers to things that belong in the past. The term let bygones be bygones is quoted in Proverbs, published by John Heywood in 1562 to mean leave the unpleasantness between us in the past. When used as an adjective before a noun, the term is hyphenated as in let-bygones-be-bygones.
Up to the point of vile mistreatment, your dog is more than willing to give you the benefit of the doubt on any issue, and let bygones be bygones — endlessly. (The Black Hills Pioneer)
Oasis fans have been hoping for years that the band might get back together for new shows, and you would think if anything could force Liam and Noel Gallagher to let bygones be bygones it would be the love of Manchester. (The Independent)
“We are excited to finally be invited to the table, and it’s time to let bygones be bygones,” said Baber. (The Beckley Register-Herald)
Even if the facts bear out the complaints, we’ve demonstrated a surprising propensity to forgive entertainers on the subject of sexual harassment or sexual battery; witness the let-bygones-be-bygones attitude many music consumers took toward Chris Brown when he released a new album this sprinG. (The Los Angeles Times)