a ninja move is when you or someone else does something behind your back or you do it behind theirs. this can be used in almost any tense. the reason behind this is well think about it ok. ninjas do shit and get away with it without being seen whether they are doing good or bad things to people.
1. i just pulled a ninja move on jon and fucked his girlfriend when he was in the room next to mine.
2 i just ninja'd that cop. he believed i was the guy in the pic on my fake drivers license.
3.did you just see me ninja that fucker that stole my weed earlier and he didnt think i knew who did it? he was knocked out cold and has no idea who blasted his punk ass in the dome.