1. What does it mean?
복붙 shortens 복사 and 붙여넣기. It can describe the ordinary act of copying content into another place, or something so similar to another that it seems copied.
Also written or said as 복붙하다, 복사 붙여넣기, bokbut
2. The nuance
It is neutral when describing a computer action. In a complaint about repeated replies or assignments, it can suggest a lack of effort or originality. The word alone does not establish plagiarism or who owns the content.
3. Examples
“주소가 길어서 직접 치지 않고 복붙했어.”
The address was long, so I copied and pasted it instead of typing it.
“형제 고양이가 같은 자세로 자니까 복붙한 것 같아.”
The sibling cats are sleeping in the same pose. They look copy-pasted.
Sources
Journalists Association of Korea: language in use
References support the meaning and usage. Example sentences are written for NoCapWiki.