When trying to respond to a comment on a chat room, only for someone to comment before you, making your comment lose it's original Context. Depending on the intermediary comment, this can have some humorous results
To take something quickly and quitely without anyone noticing. Offen used in the onlinegameWoW when a party member takes an item without the party's consent.
Tim: Dude you gotta see my new phone it's so boss.
*tim reaches in his pocket for his phone*
Tim: What the hell, who ninjad my damn phone?
Mike: oh dude I thought you knew I was looking at it like 5 minutes ago.
Tim: How the??
1. v. The past tense form of taking an item from a person without their noticing, usually right in their line of vision.
2. Used in the popular game "Halo" for xbox 360 when a player is getting chased down by another from behind, jumps backwards, and assassinates the enemy. (past tense)
when someone ninjas you it means they send you a chat on facebook saying either ninja, you've been ninjad, ect. knowing that are logging off right after it sends.
*kate opens up facebook chat and sends a message to john saying 'i just ninjad you' then logs off*
john: dang it she did it again
kate: hahaha he can never ninja me back...i must be too ninja