A Casey is a person (male or female) who acts happy and brave, while there inner most thoughts are ones of sadness and depression. Caseys are shy and they don't tell you these depressing thoughts, but they wear a smile to keep everyone else happy. These people are a danger to themselves.
On an interpersonal level, a Casey is kind, loving, caring, sweet and intelligent. They often are socially awkward and shy, but once one gets comfortable around you, they are a great asset to have.
"That guy is so nice. It's a shame that all his smiles look forced. He's a real Casey"