puzzleheaded

/ˈpʌzəlˌhɛdɪd/
adjective
  1. Having a confused or disorganized mind; unable to think clearly.
    • The puzzleheaded student kept mixing up the dates in history class.
    • She gave a puzzleheaded look when asked to explain the complex theory.
    • After the long flight, I felt too puzzleheaded to follow the instructions.
Antonyms