A playground dialect employed to signify that you mean the opposite of what you’re actually saying. The technique is achieved by pulling your lower lip back over your bottom teeth, and making a whooshing sound as if you’re describing how something has flown across a room (such as a paper aeroplane or frail child). You have to pronounce each letter ‘s’, and the end of each word where possible, using this method. Sounds complex but it’s easily done.

Let us illustrate this with an example.

Kid A: Look at the state of David Barnes’ [bag / coat / shoes / pretty much anything you care to mention]. What a fucking gyppo.
Kid B: Yeah I know. He’schh not a shcruffy cunt at allschh.
Kid A: He doeschhn’t schhtink of schhit muchschh.
Kid B: And hiscch houseschh is dead cleanschh.

Using Yish, Kids A & B have successfully pointed out that David Barnes is in fact a dirty, smelly, scruffy tramp from whom, by inadvertently smelling his breath, you would certainly catch Aids. Yish can also be used safe in the knowledge that if you are overheard by a teacher when ‘praising’ something in this way, the teacher is unlikely to be bothered to find out if you are being sincere or not.

Warning: Yish is not effective as a comeback if you are accused of being gay. It is no use simply saying ‘yeschh I’m really gayschh’, because that just means you really ARE gay, and therefore deserving of a kicking and having everybody find out that you’ve bummed your dad. No reason, it just DOES.