Muzzy
/ˈmʌzi/
Definition 1 of 2
Pro Tip 1/3Feeling Unclear
Used when your thoughts are not clear, like you can't focus or feel confused. 
After studying all night, she felt muzzy and couldn't concentrate.
Pro Tip 2/3Not Just Physical
It describes a mental state, not just feeling physically blurry or dizzy. 
Even though he wasn't sick, the news left him feeling quite muzzy.
Pro Tip 3/3Temporary State
Often refers to a temporary condition, not a long-term trait. 
She was muzzy for a few minutes after waking up from her nap.