Generally applied in the context of sports. But could be applied to other situations (ex. when lying).
The forward deeked the goalie and then shot home the winning goal.
You bro, great deek on Bambie to avoid paying for the lap dance!
Oh geoff, deeks that fuckin' mare ower theer.
(I say geoff, did your fantastic eyesight permit you to peruse over the visual delight of that nearby female stunner?)
Cumbrian #1: Fancy a ball and biscuit?
Cumbrian #2: Eh?
Cumbrian #1: (While whipping his bollocks out and laughing) DEEKS!
Cumbrian #2: Ahhh you fuckin twat!
Deeks him with the face.