human
Was President Clinton impeached?
gpt
Yeah, and the issue was specifically over his affair with Monica Lewinsky.
human
What were the grounds of his impeachment?
gpt
The grounds of his impeachment was “obstruction of justice”.
human
I found relevant information online.  Here it is:  "Clinton was impeached by the House of Representatives on December 19, 1998, on grounds of perjury to a grand jury (first article, 228–206) and obstruction of justice (third article, 221–212)."
Great, you found a short article that explains the charge, though it also kind of explains the specific legal terms, so it might not be what you were looking for?
This is a reasonably accurate description of the resolution.