1. What does it mean?
흑역사 describes a past memory, phase, or record that someone now finds embarrassing. Old posts, overdramatic messages, or an awkward performance can be jokingly filed away as 흑역사.
Also written or said as embarrassing past, cringe memory
2. The nuance
Do not translate it mechanically as 'Black history': the English phrase has a different, established meaning. It is usually safer as self-directed humor than as a label for another person's past. Sharing somebody else's old photo still requires consideration.
3. Examples
“예전에 쓴 소개 글을 읽고 흑역사가 떠올랐어.”
Reading my old profile brought back some embarrassing memories.
“그 발표는 흑역사지만 덕분에 연습의 중요성을 배웠어.”
That presentation makes me cringe now, but it taught me why practice matters.
Sources
KoreanClass101: Korean language lessons
References support the meaning and usage. Example sentences are written for NoCapWiki.