Peter's Strange Word

Question

My nephew, Peter, came home from school the other day in a bad mood so I asked him what was wrong.
"Our teacher asked us to write down our favourite word today," he explained. "When I gave her mine, she told me it wasn't a real word."

Intrigued, I asked him if he could tell me what the word was. He wrote it down on a piece of paper.
"I think you've just misspelled it, do you mean this?" I wrote down what I though was the correct version and handed it to him. "I have some of those in my house," I added.

"No!" he exclaimed. "This is a different word."
"Really? How do you define it?" I asked

This was his explanation

"For each one of it, I hit the sound.
If it's not it, we can consult.
Jointly, it will knock you out.
With death, there will be a result."

Looking at the piece of paper I could understand what he meant, although one of his explanations was a stretch. "Maybe it should be a word," I conceded.

What is Peter's strange word?
Please explain each line in your answer

Answer 1

I think your nephew is thinking of the strange word

cussion

For each one of it, I hit the sound.

percussion is a musical instrument that you need to "hit" to hear a sound(per = each one)

If it's not it, we can consult.

discussion means to consult (dis = not)

Jointly, it will knock you out.

concussion is a knock out (con = jointly)

With death, there will be a result

repercussion means consequence or result (reper maybe like the Grim Reaper who symbolizes death)

And in your house you have many

pillow cushion which sounds similar