A rather elaborate yet highly description term for a Gash.
This should be used in context with an unclean cunt. The 'cheesey' referring to the fanny batter appearance and the 'salmon' not only being rather descriptive of the smell but also on occassion the colour of the beef curtains. The beef curtains or piss flaps are indeed aptly referred to as 'slots' in the phrase being outlined.
Person 1: Hey brah, you wanna go get some pizza?
Person 2 : CHEEEEEAYAH
Person 1: what does that mean?
Person 2: doode indeed i would like to go get some pizza "CHEEEEYAH"