Someone who is willing to have sexual intercourse with men older than 50.
Commonly used in gay-language.
Other term: Dirty Old Faggot, Menlover, Let-me-show-you-my-dick
Also used as a verb or adjective.
Dude, are you a Stronghorn or something?
Your Mum is a stronghorn
OMG he stronghorns again. Everyone RUN!!
Stop stronghorning me dude. I'm NOT gay
Life is so stronghorn
Also used as an insult:
Son of a Stronghorn.
Fuck you, fucking stronghorn!