cloud head
Old person with grey hair.
Don't go in that pub, it's full of cloud heads.
head cloud
The condition of being slow witted or mentally fatigued, often brought about by sleep deprivation, partying, overworking or over studying, excessive use of television, video games or computer time; cognitive atrophy. It will feel like there is a cloud where your brain should be making it hard to think, concentrate, solve problems, or keep up with conversations.
I feel out of it today man, I have a serious head cloud right now.