spec - spectacular/special. A new hip catchword that all the kids will be saying in the following year. It's cool, it's catchy, it's now, it's wow, it's spec!
'Spec', pronounced 'spess' is derived from the word specimen. It is an insult. It implies a resemblance to unpleasant medical specimens such as stool samples, parasites and such like, or perhaps quality control failure samples which have been kept for reference.
What do you think you're doing wanking in the shower at swimming lessons? You are such a spec!