This is the 8423rd most frequent Russian word.
назад
"Назад" means "back" or "ago."
Here, 'назад' indicates 'back' in the sense of returning to a prior location or state.
Я вернулся назад через час.
I came back after an hour.
In this sentence, 'назад' means 'ago', referring to a time in the past.
Пять лет назад я жил в Москве.
Five years ago, I lived in Moscow.
Here, 'назад' again means 'back', as in there being no way to return along the path or road.