Unfit For Purpose 

This expression originated with the Royal Navy where stores or equipment were found to be damaged, wouldn’t work or could not be used for the purpose for which they were intended. The expression quickly found wider usage and is now applied to not just stores and equipment, but to organisations, designs even concepts. It can also be applied to co-workers if they are not doing their job properly and, in extreme cases, used as a put down where someone is a complete arsehole and unsuitable to be considered part of the human race.

Malcolm you are unfit for purpose.

Unfit For Purpose by AKACroatalin April 23, 2015

unfindoutable 

Incapable of being found out about; impossible to find out.

So Yesterday, my nephew decided to tell a secret to my grandparents, and I could not hear it, and they refused to tell me the information. It is now unfindoutable

unfindoutable by Qwickable March 27, 2019

unfiltered friend 

That good friend with whom you can be your authentic and unedited self.

I’d much rather hang out with you, my unfiltered friend!

unfiltered friend by Dr Bunnygirl September 26, 2019

unintenuendo

An innocent phrase full of unintended innuendos.

I got new mounting brackets and insulation for my hot water pipes to keep them lifted and separated so they don't rub together and bang all night. I'm going to sleep so much better now with my plumbing properly mounted! Whoops, that was an unintenuendo.

(see Sexually Oblivious Female meme)
Unintenuendos provide great opportunities to say, "that's what she said!"

unintenuendo by just4titsNjiggles January 13, 2021

Unintentional Flexing 

One of the greatest honours one could receive and the highest Level of flexing when you are so fly it gives the illusion that you don't to put effort into flexing, you just flex naturally. It doesn't involve buying for the brand and the common hypebeast would be unfamiliar with this concept.

Jack: Yoooo look at Rice Gum's new oufit isn't that freshhh
Jill: Na bro it just screams supreme, how does that make it freshhh, he doesn't even look good. He's trying hard it's Inentional
Jack: Ahhh right brooo I get you!
Jill: Check out A$AP ROCKY thoughhhh freshness is in his blood. He's unintentional flexing

Unintentional Flexing by FlexOffender101 July 9, 2018

Unfinished Jizzness 

When you've been at it with the missus all night and it's time to get ready for work... a disciplined man will leave the scene and face his responsibilities while letting her know that is there is definitely some unfinished jizzness...

Mate, me and Karen were like animals all night, haven't slept.. only reason we stopped and I got to work on time, was because we agreed there was unfinished jizzness...

... (pause..... )

...... you reckon the gaffer will give me a half day... ;P

Unfinished Jizzness by JamboLAD September 4, 2021

uninteractive 

A made-up word you try to use when describing something that is not interactive. The word you are looking for is noninteractive.

You are a very uninteractive person.

That doesn't mean anything, sorry.

uninteractive by johnsee166 October 8, 2018