ácido
/ˈaθido/ · B1 · adj
acidic
🍋 ácido = English acid, from Latin acidus, sour
Both come from Latin acere, to be sour, which also gave acetum, vinegar. Spanish says the c as th in Spain (A-thee-do), and the stress falls on the first syllable. It works for a tart lemon and for a harsh, biting remark.