What is the significance of the word "nada" in Hemingways "A Clean, Well-Lighted Place"?

The word
"nada" in the story stands for the nothingness that the waiter who is not in a hurry
fears. He understands the old man's desire to drink in a clean, well-lighted place, though the
old man can just as easily drink at home. A clean, well-lighted place is a kind of defense
against the nothingness, or emptiness, that plagues all humans.

Towards the
end of Hemingway's story, the waiter thinks of the Lord's Prayer interspersed with the word
"nada," beginning, "our nada who art in nada." The use of the word
"nada" in the Lord's Prayer is another form of expressing the belief in nothingness,
as the words "God" and "heaven" have been replaced with it. In other words,
the waiter does not believe in God, and, without this belief, he is faced with a kind of
crushing emptiness and fear that causes him insomnia. His only relief is to find temporary
respite in a clean, well-lighted place like the bar.