Intentionally botching the grammar of a sentence. Also the misuse or pronunciation of a word within a crowd of literary proficient individuals.
The act of dropping a grammar bomb is most effective at parties where most guests are highly educated, or pride themselves in having an intimidating vocabulary. There is a careful balance in placing a grammar bomb as to gauge the reaction of other people. Too subtle, and nobody might even notice. Too strong, somebody might correct you. (still kinda fun) The optimal priming for a grammar bomb is when everybody heard the language atrocity, but feels compelled to behave politely and endure the awkward moment without correction.
“Hey, I dropped a grammar bomb in front of that English professor who knows I have a Master’s Degree. I think it broke his brain.”