Top definition
When you do something you know you're not supposed to do (whether it's good or not so good) or when you do something that other people (like your parents) don't want you to do.
by avtor17 February 07, 2018
2
Damn my in-laws are visiting again! Gotta go on a ninja mission to get high!
Sarah just got a new girlfriend. She works at the mall. Ninja mission?
Marah just had her baby, let’s go on a ninja mission tonight and drop off some food!
Sarah just got a new girlfriend. She works at the mall. Ninja mission?
Marah just had her baby, let’s go on a ninja mission tonight and drop off some food!
by YubNub83 September 05, 2019