This is the 13813th most frequent Russian word.
ночами
"At nights" or "during the nights."
Adverb of time
Он часто работает ночами.
He often works at nights.
Adverb indicating a recurring time context
Ночами в деревне тишина и спокойствие.
At nights in the village, there is silence and tranquility.
Describes a continuous action happening during nights repeatedly