This is a reasonably accurate description of the resolution.
assistant
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?
assistant
Was President Clinton impeached?
user
Yeah, and the issue was specifically over his affair with Monica Lewinsky.
assistant
What were the grounds of his impeachment?
user
The grounds of his impeachment was “obstruction of justice”.
assistant
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)."
user