This is the 602nd most frequent Turkish word.
acı
"Acı" means "pain," "bitter," or "spicy," depending on the context.
Here, 'acı' refers to the taste of the tea, meaning 'bitter'.
Bu çayın acı bir tadı var.
This tea has a bitter taste.
In this sentence, 'acı' describes a physical sensation, translated as 'pain'.
Kardeşim düştüğünde acı çekti.
My sibling felt pain when they fell.
Here, 'acı' describes an emotional response, signifying that the departure caused emotional pain.