Like the face of someone who has just bitten into a lemon.
If you mean carboxylic ACID: yes that is (a bit) sour
"Sour look" is an idiom for an expression of distaste or annoyance.
A sour face is usually pursed lips, squinted eyes, and sucked in cheeks. It doesn't necessarily mean one ate something sour, but it looks as if they did.
Yes
sour
Tasting sour
a hateful/mean/unpleasant person
by mean types do you mean like salty,sour...or do you mean like fluid...?
residue from making butter from sour milk
Surd is not a Swedish word. Sur, however, means sour or cranky. Surdeg is the Swedish word for sour dough.
"sharp" Just as in English, it can mean "piercing" for a sharp and shrill noise, "acrid" for a sharp, bitter taste, "keen" as in a sharp mind, and so on.
It is yellow and sour.