She was real salty when she got the answer wrong in class, especially since she swore she knew the answer.
another way to describe Tsukkishima from Haikyuu, an anime that somehow makes all the side-characters more famous then you imagine.
Kuroo: AYO SALTY
Tsukkishima: ugh what?
When someone is being toxic, or a bad sport.
Jackson: Dude why you gotta be so Salty!
Ryan: Wish I knew bro!
A salty person tends to find the negative in every thing or is just rude af for no reason
I said "Good morning Jake"
Jake was like "What's so good about it"
I said "ew your mad salty"
Or one doesn't acknowledge your lighthearted mood
Joking around and they take things too seriously.