What does "Crackhead" mean?

"Does crackhead mean really happy?" My professor asked. The class broke out in laughter. "I am serious, what does crackhead mean?"

This question came after a fellow classmate held up a picture of Julia Child and described her as a "crazy crackhead cook".

I suppose I should add that the picture was supposed to represent the word "happy" for an in-class project.

I actually loved my teacher's honesty. Even in the midst of all of the laughter, she was still waiting for the answer and asked the question until she got her answer. She told the class that she was always learning something new and wanted her students to teach her.

I want to be like that, always asking questions no matter how ridiculous I sound.

P.S. Crackhead is a term for someone on crack. :-)