After pulling an all-nighter, he felt too muddleheaded to concentrate on the exam.

The committee dismissed the suggestions, calling the opposing members muddleheads after a heated debate.

Don't be such a muddlehead—read the instructions before you start.

After three sleepless nights, her muddleheadedness caused her to forget the appointment.

She muddleheadedly left her notes at home and then tried to remember what she had planned for the meeting.