| 1. | past; gone by; earlier; former: The faded photograph brought memories of bygone days. |
| 2. | Usually, bygones. that which is past: Let's not talk of bygones. |
| 3. | let bygones be bygones, to decide to forget past disagreements; become reconciled: Let's let bygones be bygones and be friends again. |
Let past offenses and problems stay in the past; don't let them taint the present.
let bygones be bygones
What's done is done; don't worry about the past, especially past errors or grievances. For example, Bill and Tom shook hands and agreed to let bygones be bygones. [First half of 1600s]