A Thing - A thing is when you can't remember the name of something and

A thing is when you can't remember the name of something and you just say 'a thing' instead. It's lazy, but it works.

I saw a thing that looked like a dog but it was a cat. It was confusing.

My brother tried to name his thing. He failed.

I saw a thing in the hallway. I didn't know what it was.