An individual who takes joy in being the first to break big news. He or she rushes with lightening speed to contact all of your friends and family before you get a chance to.
Victim: So I got that promotion! I'm so stoked!
Friend: Yeah I heard, Bob called and told me. Congrats.
Victim: But I just found out like 10 minutes ago! He's such a thunder stealer!
One of your "questionnable" friends who, when you try to set up your other friend with some chicks, comes by and steals the attention from said friend. thus making him a communist,thunder-stealing, jerkface!; Also makes you feel like a jerk because your well thought out plan to hook up a friend goes horribly wrong.
"Hey mauro, go talk to those chicks!"
"nah, jesse will steal my thunder and i'll have to go home and cry..."
"yeah, you're right.screw that thunder stealer"
A thunder stealer is a very annoying person who bursts in to your conversation and changes the topic to him/herself. Usually leaves you aggravated.
Bob: Hey guys LISTEN! You won't believe what happened today!
Bob: Well i was walking down some alley when i got jumped by three guys with-
Thunder stealer: OH HEY JACK did you do yesterday's homework!?
Jack: Oh yeah, it was pretty easy
Thunder stealer: Hahaha, yeah. Hey can you show me something in the homework? It's on page 54...
Bob: Hey what about my story...
Someone who deflates your ego and morale by taking your work and passing it off as their own OR says it's not that impressive.
I sent Steve this link last week and now he's pretending he came up with on his own. Why's he gotta go and be a thunder stealer!?
An asshole who attempts to steal the attention of another at a certain time.
Victim: "Dude, i just beat my guy at a wrestling match, 6-3!"
Thunder Stealer: "Yeah, well I pinned my guy."