coconut brain

1:Describes someone who is so empty-headed, or stupid that it seems that there are no more braincells in this persons head, that this persons head can be described as a coconut, which is a blank empty fruit.

2:Another meaning: no thoughts in ones head.

1:He's been rambling on about cocomelon for an hour, such coconut brain activites.
2:Dude, shes been staring at the abcs for 10 minutes now, its giving coconut brain activites.