Top definition
When you or someone else insults someone in their head

Can be used while also saying something nice outloud
Timmy: Hey buddy I got the iphone 6+

Tommy: (thinking) why don't you shut the fuck up u faggot I'm bout to slap the tiny dick off you

Tommy: (saying) oh that's cool Timmy

Timmy: (thinking) the fuck did u just mental insult me u retarded meatball
by Oibun Dikshunaree October 28, 2014
Happy St. Patties Day!