This is the 15907th most frequent Russian word.
прорубь
A hole cut in ice, often for fishing or bathing.
In this sentence, 'прорубь' refers to a hole cut in ice usually for religious or celebratory purposes.
Мужчины ныряли в прорубь на Крещение.
The men were diving into the ice hole for Epiphany.
Here, 'прорубь' is used to describe a functional hole in the ice made for fishing.
На рыбалке он просверлил небольшую прорубь для ловли рыбы.
On the fishing trip, he drilled a small ice hole for catching fish.
In this context, 'прорубь' simply describes an ice hole that is part of the winter setting of a shore.