sour or tart in taste or smell, like vinegar; spoiled or fermented food

acid, a chemical compound that releases hydrogen ions in water

sore, aching, or tingling, usually due to fatigue or illness; same as 痠 suān

pedantic; impractical; miserly

(bound form) sick at heart; grieved; distressed, such as in 心酸 xīn​suān

(slang) jealous or envious, especially in the context of being "salty" or making cynical comments about others' success

a Chinese surname

to make sarcastic or stinging remarks; to mock someone using irony