This is the 1172nd most frequent Russian word.
вечера
"Вечера" is the plural form of the Russian word "вечер," meaning "evenings."
Here 'вечер' is used in its singular form to denote the time period of 'evening' in a locative sense.
Вчера я провёл прекрасный вечер в парке.
Yesterday, I spent a wonderful evening in the park.
'Вечера' is the plural form here, signifying the general notion of evenings as a recurring time of day.
Вечера становятся длиннее весной.
Evenings become longer in spring.
This usage of 'вечера' in plural highlights specific instances of evenings recalled from the past.