"What does that mean?" joke

Once there was a room with one scientist and one blonde. The scientist was very playful and loved to play games. The blonde was very serious and hated life and was very serious. She also hated games. The scientist wanted to play a game. "
Do you want to play a game?"
the scientist asked the blonde. "
Okay. I guess,"
the blonde said in a bored voice. "
Here are the rules,"
said the scientist,"
I will ask you a question. If you answer it correctly, I will give you $
9999999999999999999999999999999999999999999999999999999999999."
That made the blonde want to play. The scientist said,"
Here is your question.What is the hypothosis of a pickle?"
The blonde didn't know only one word of it. She asked what the word meant. "
What does the word a mean?"
she asked.