When you do something that’s going to end in certain failure but you decide to do it because it’s your obligation to do so. It’s also a very British thing to do.
Can be used in a video game context when you sacrifice yourself for the better of the team.
Variant : suicide mish
Dude1: Cya dude im going on a suicide mission and gna call my ex up about going out again.
Dude2: Instant death.

Dude1: No he’s got a rocket launcher.
Dude2: Don’t worry I'll go outside on a suicide mish and waste his ammo.

Dude1: Dude I got this girl into my room and I was so horny i asked her to suck me off, I thought i was on a suicide mission, but she unzipped my pants and sucked it like a pro whore.
Dude2: Lucky fuck, can I have her number?
by Andy2billion July 3, 2005
A controversial statement made by President Donald Trump in response to North Korea's recent nuclear missile launches which may be a potential threat towards the United States...
Trump: The Rocket Man is on a suicide mission.
Me: Hmm...catchy but debatable statement...
by SnellyBob JoeSpends September 23, 2017
Go to any convenience store and fill your cup with all flavors of soda from the fountain. Skipping the diet versions of course.

Also Suicide Sundae... Any toppings you have on hand on top of whatever ice cream in your freezer! Any type of fresh, frozen or canned fruit, chocolate, nuts, jellies, syrups (caramel, strawberry, maple, maple flavored, butter) and candies you desire to try even cough drops!

Or Rainbow Suicide - A little bit of all flavors of fruity frozen drinks in your cup... Can be done on a snow cone!
Wanna go on a suicide mission with me? No I do not, you know its illegal to kill people, dude calm down, we are just going to go get soda from Quiktrip, you better be telling the truth!
by Reallybadgenius November 19, 2022