What does bygone mean?
"Bygone" is an English word describing anything that belongs to an earlier time—something past and finished. As an adjective, it typically appears before a noun to lend a sense of nostalgia or historical distance, as in "bygone days," "a bygone era," or "customs of bygone times." It carries a gently wistful, often affectionate connotation, making it a favourite of historians, travel writers, and anyone reminiscing about the past. Bygone also functions as a noun, though almost always in its plural form "bygones," which survives today almost solely in the well-known idiom "let bygones be bygones"—an invitation to forgive old grievances and move on without dwelling on them. The word is formed simply from "by" plus "gone," literally meaning something one has gone by. Its useful contrast words include current, modern, and contemporary. Whether describing obsolete technology, vanished customs, or quarrels best forgotten, "bygone" offers writers a compact, evocative way to signal that something belongs irrevocably to the past.
Belonging to or characteristic of an earlier period of time; past.
"Visitors can admire carriages from a bygone age."
Typically used attributively (before a noun), often with a nostalgic tone.
Something from the past, especially a former grievance regarded as best forgotten.
"The rivals shook hands and let bygones be bygones."
Almost always used in the plural, and nearly always within the idiom 'let bygones be bygones'.
The noun is rarely used except in the plural, and almost exclusively in the phrase 'let bygones be bygones'.
"They decided to let bygones be bygones and resume their friendship."
The phrase 'let bygones be bygones' has been urging people to forgive and forget since at least the 16th century—and 'bygones' is one of the few nouns we almost never use outside a single famous idiom.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bygone
Bygone is a compound of the preposition "by" and the past participle "gone," literally meaning "that has gone by." It emerged in English around the late 15th century, first appearing in Scottish usage before spreading into broader English. The related noun "bygones" developed later, becoming firmly established through the proverbial expression "let bygones be bygones." The same productive prefix "by" appears in other English words such as "bylaw," "byway," and "byword."
Related word forms
How bygone is actually used
Mostly literary or nostalgic in register when used adjectivally, often evoking affectionate wistfulness rather than criticism. The noun occurs almost exclusively in the fixed expression 'let bygones be bygones'.
Easily confused with bygone
'Foregone' means having gone before or already decided (as in 'a foregone conclusion'), while 'bygone' refers to things belonging to an earlier time.