What is monicagate?

Answer 1

A great scandal which brought ruin to US President Richard M Nixon was a break-in to the offices of the Democratic Party in the Watergate Hotel in Washington.

Following this the suffix "~gate" was often appended to any scandal, or potential scandal involving prominent politicians. The main requirement for using the word was that there ought to be some degree of lying, or manipulation of the truth on the part of of the main character

US President Bill Clinton got into a lot of difficulty centred on his relation to Monica Lewinsky... which some in the media referred to as Monicagate, as it was widely held that Clinton was - to say the very least - less than honest in what he said about the relationship.