From the Afrikaans word 'kak' meaning 'shit', but stronger.
'Verkakt' is an American hybrid word used a) when referring to the ultimate let-down; b) referring to the actions of a douchebag; or c) simply as a substitute for 'shit'.
a) After spending so much time getting to know her and enjoying her company, he just suddenly changed his mind? That's verkakt!
b) His verkakt behavior when he one-night-standed his best friend.
c) This weather is verkakt.