This is the 180th most frequent Ukrainian word.
тих
"Тих" in English means "quiet" or "silent."
'тих' is used as a demonstrative pronoun modifying 'лісах' (forests), meaning 'those' to refer to specific forests.
У тих лісах чути співи птахів.
In those forests, one can hear the singing of birds.
Here, 'тих' functions as a demonstrative pronoun referring to 'вечорів' (evenings), implying specific or previously mentioned evenings.
Мені подобається атмосфера тих вечорів.
I like the atmosphere of those evenings.
'тих' serves as a demonstrative pronoun connected to 'пагорбах' (hills), specifying which hills are being discussed.