Definition of a 'brony'?

Brony, n.
A term for a male ファン of MLP; FiM, who is 'too old enough' to watch it. It has recently branched out as a term to everypony who watches & supports the show.

Other MLP; FiM definitions:
Pegasister, n.
A term for a female ファン of MLP; FiM. It is hardly used now, as female ファン are now called 'bronies' instead.

Steven Magnet, n.
Steven Magnet was a purple & yellow sea serpent, who's only had an appearance in Season 1, episode 2 so far. He got his name from a YouTube video when Youtube's inaccurate (But humorous) captions had the name 'Steven Magnet' pop up.

/The Great and Powerful/ Trixie, n.
1. The Great and Powerful Trixie. Duh.
2. A character known as Trixie, whose only appearance was in Season 1, episode 6. She held a magic 表示する in Ponyville, 表示中 off her tricks. The mane six thought her attitude during it came off as cocky, and thought she was a show-off.

Flutterguy, n.
Flutterguy became a sort of meme/fad when Fluttershy's voice deepened in season 1, episode 9. The most 人気 meme/fad of Flutterguy was the portion in the episode, in which Pinkie Pie was unable to talk/sing properly, due to her tongue. This lead her to ask Flutterguy to sing a もっと見る jazzy, slow version of 'Evil Enchantress', the song Pinkie Pie sang in the episode before her tongue was cursed によって the Poison Joke.

Trollestia, n.
Princess Celestia got this name from the MLP; FiM fanbase, when bronies pointed out things she did that seemed troll-worthy.

A brony is basically a male ファン of MLP.

Brony. Noun. A name typically 与えられた to the male viewers/fans of the My Little ポニー franchise.

Female variation of this word is believed to be "Pegasistah"

A Brony is technically a young adult male ファン of My Little Pony: Friendship is Magic.
But the タイトル branches out to others; basically any ファン of the 表示する who is male, または "too old" for it.

A brony is an adult male who watches または is a ファン of Mlp:Fim.They think the 表示する is addicting as we read コメント in youtube.They became a brony when the episode ''The Ticket Master'' aired.Bronies were named after 4chan,I think.

*points at PhoenixRoyale's answer* ._.