So I've been wondering where all these My Little Pony avatars have been coming from for a while now, and I finally had the free time to look up the show, My Little Pony: Friendhsip is Magic (AKA the least manly title in the history of ever). After watching the first episode I mostly loled, but was like, "well it's to be continued. I have to watch the second episode to." I'm now four episodes in and ashamed of myself.
Urban dictionary definition
Brony-A name typically given to the male viewers/fans (whether they are straight, gay, bisexual, etc.) of the My Little Pony show or franchise. They typically do not give in to the hype that males aren't allowed to enjoy things that may be intended for females.
Example

erson A: So I was listening to this song called Winter Wrap Up, and it just got stuck in my head...
Person B: Winter Wrap Up? What kind of name for a song is that?
Person A: What? You haven't heard that song? It from the episode of My Little Pony where?
Person B: I no longer give a fuck.
Person A: Relax! I'm just an awesome Brony who is?
*Person B punches Person A across the face*