This is the 2052nd most frequent Russian word.
вечерней
"Вечерней" means "evening" or "of the evening" in English.
In this sentence, 'вечерней' is an adjective modifying 'кофейне' (café), indicating that it is an evening setting or establishment.
Мы решили встретиться в вечерней кофейне.
We decided to meet at the evening café.
Here, 'вечерней' acts as an adjective describing 'атмосфере' (atmosphere), signifying it relates to the evening mood or environment.
Её платье соответствовало вечерней атмосфере.
Her dress suited the evening atmosphere.
'вечерней' in this case is linked to 'программе' (program), emphasizing that the program takes place in the evening.