Pronunciation: (bī'gôn", -gon"),[key] —adj. past; gone by; earlier; former: The faded photograph brought memories of bygone days.
—n. 1. Usually, bygones. that which is past: Let's not talk of bygones. 2. let bygones be bygones, to decide to forget past disagreements; become reconciled: Let's let bygones be bygones and be friends again.