So I finally found the source of the coolant leak I've been having and it's coming from this joint. I dunno what part this is called, but here are some pictures.

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What's this part called and how should i go about fixing it? Thanks!!

 

Did you move the hose clamp up?
You can see the marks it left on the hose, that is where it should be.

 

not likely leaking from the metal connneciton, rather the hose and dripping down the metal pipe. If it truly is the metal pipe you need to replace the entire manifold as it is not as separate part. It looks like a hose and clamp issue. Double check that the bleed bolt is tight, if it is loose it can leak down to that point.

 

is this a trick question? put the hose clamp back

 

Spring clamp is too high up. Move it down just below where the hose fits over the flared part of the metal pipe, but above where it was originally.

 

Let's say someone working on the car forgot to put the clamp back and it has been leaking for a while.
If that is the case just putting it back may not work.
4-5 years ago I had a coolant leak from the thermostat joint, bigger diameter hose, that was leaking for some time, maybe 2-3 weeks, it was slow leak.
Once I removed the old hose I found some weird stuff on the pipe nipple, much like clear cake icing with a smooth surface.
I guess it was some residue from the coolant.
It was not easy to remove, I had to use Scotch brite.

FYI.

 

That's a combo of oxide and mold, seen it many times doing validation for industrial HVAC systems.