Or maybe gravy?
None of the above. (As in, I’m trying to get into the mindset you’re in to ask this question, and I just cannot come up with anything to justify any of those answers. Sauce would probably be the least wrong of the answers, but it’s still wrong.)
I wouldn’t consider it any of the three. I’m not sure what I would call it if I were pressed. Ingredient, I suppose. Not enough has been done to it to be a sauce, broth or gravy.
I add sugar. That makes it a sauce.
It’s milk.
It’s a condiment, like syrup on pancakes.
It’s an ingredient.
Water or broth is an essential ingredient in all versions of the dish soup. Milk is an essential ingredient in all variants of the dish milk-and-cereal.
No, the milk is not ON TOP OF the cereal. The cereal is IN the milk.
What do you call the part of stew that isn’t the chunks of meat or vegetables? That’s the closest analogy I can think of right now.
It’s a bad idea. Try yoghurt instead.
j
Edible suspension medium.
Etymologically, the closest equivalent would be soup, which derives from the word “sop” — as in milksop, ie bread soaked in milk. As Thudlow Boink correctly pointed out, the cereal is in the milk.
Of those, broth makes the most sense. Gravy is thickened broth, and even sauces are a little thicker.
That said, the term really only applies to plant based milks, since they are made with water and the part of the plant in question. Scrolling up, I’ll agree that “soup” is the better ally encompassing word.
None of the above.
If you’re referring to the leftover milk after eating all the cereal out of the bowl I think we typically refer to it as “cereal milk”.
I think it is broth. Sauce and gravy are both eliminated as I would never eat/drink the remains after the main ingredient is consumed. Also when consuming sauce and gravy, most people would actively try to utilize the potatoes/biscuits/food to sop up and utilize the sauce or gravy to their fullest.
In this case milk is broth as it is consumed afterwards and similar to broth there is no way to actively sop it up completely.
I’ll second this.
This is the right answer. IMHO.
Also allowed. 
Sometimes the categorization of various things is useful for learning and understanding the world around us. Sometimes it’s stupid and useless.
It’s taking longer than we thought.
Scientific progress goes “Boink!”
That’s the beauty of it!
Of the three options, it’s closest to being a sauce - the cereal isn’t cooked in it, nor is it cooked using a byproduct of creating the cereal.
But it’s not that, either, due to lack of processing as said.
(And Pop Tarts aren’t ravioli, either.)
If you look at the dictionary definitions of sauce, broth and gravy you’ll see milk doesn’t fit any of them. This isn’t a philosophical question.
Sauce: thick liquid served with food, usually savory dishes, to add moistness and flavor.
Broth: liquid in which meat, fish, cereal grains, or vegetables have been cooked
Gravy: a sauce made from the thickened and seasoned juices of cooked meat
So I guess it’s closest to a sauce because it adds moistness. In that case, hot water on your shredded wheat is also a sauce.