someone who sets himself up to laugh, either alone or in a group. this person instigates a specific response from people just to make himself laugh
Guy 1 knows what Guy 2 is going to say beforehand, making him a laughterbater
Guy 1: "What are you wearing?"
Guy 2: "Nothing!"
Guy 1: "Hahahahaha."
1. One who makes one's self laugh, or a person who laughs at their own jokes.
2. A person who is turned-on by their own laughter.
If only Steve were as funny as he thinks he is; he's quite the laughterbater.