The most common and most likely answer to this crossword clue is the 5 letter word DOPED
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More clues leading to the result DOPED
Buddy explains!

The straight part
We know that "with fuzzy head?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case with fuzzy head? = doped.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DOPED mean?
DOPED verb- To affect with drugs.
- To treat with dope (lubricant, etc.).
- To add a dopant such as arsenic to (a pure semiconductor such as silicon).
- To use drugs; especially, to use prohibited performance-enhancing drugs in sporting competitions.
- To judge or guess; to predict the result of.
- Drugged.
- Describing a semiconductor that has had small amounts of elements added to create charge carriers.
- Covered with dope, a glue or paint like pore filler.