When someone'
s head is concaved inwards like a brainlet or
as if you dont have a brain. Used to
diss someone for being a retard or as a threat.
"Yo Jimmy, you know that Nick
guy? He'
s so fkn concave"
"Nick, watch your mouth or I will make you concave"
"
Pass me the cheeky Nandos or I will concave your head"