exaggerlaugher (n.), an exaggerlaugh (v.),
To laugh excessively or over-laugh; laughing obnoxiously to fill awkward silence which just makes you appear more awkward. Sometimes one exaggerlaughs for no apparent reason. Sometimes they exaggerlaugh when what someone else is saying is not even funny. Or they exaggerlaugh because something really is funny and they want to give tons of props to the person telling the joke or being funny.
"Stop exaggerlaughing, all six of us at the table think its funny too but we aren't laughing for 3 minutes straight like you are!"
Guy 1: "You want to go into the restaurant across the street? hahahhahhahaha I was in there it's great! ahahhahahahhha"
Guy 2: "no we are actually going into this one here..."
Guy 1: "hahahahhaha"