Whenever you are high and you start to get a headache. Like fr blood rushes to a dick and it’s a boner, blood rushes to the head and it’s a headache. Same thing so headboner.
Guy 1:I smoked a joint and took a fat rip of some nic.
Guy 2: I bet you had a massive headboner afterwards.
Guy 1: Oh yeah I did.
Literally a bone that sticks out of your head. similiar to a unicorn horn. It is detachable and was very stylish in the 80's. They are starting to come back into style and prebubescent girls are searching their attics and thrift stores to get there own.
Past tense for when a female wears a shirt with words on it and proceeds to judge you for trying to read their shirt. Telling you to stop looking at their chest.