This is the 3922nd most frequent Spanish word.
ácido
"Ácido" in English means "acid" or "sour."
In this sentence, 'ácido' is used as an adjective to describe the sour, tangy taste of the lemon juice.
El jugo de limón es muy ácido.
Lemon juice is very acidic.
Here, 'ácido' serves as a noun referring to a specific type of chemical compound, sulfuric acid.
El ácido sulfúrico es un químico peligroso.
Sulfuric acid is a dangerous chemical.
In this example, 'ácido' is employed as an adjective metaphorically, indicating that the comment was sharp or biting in tone.