This is a doctor's discreet euphemism, when speaking in front of the patient, to signify that the patient has a screw loose, is unhinged, a leg short of a trivet, etc.

Speaking of trivets, or perhaps not, what is a trivet screw? I don't see it listed in Machinery's Handbook.

Ah! I think you'll find that should be T-rivet screw, and it's under Screws, Rivet, T-section in most catalogues, but don't ask what they're for. However, as a face pyjama, it carries the connotation of a rather unconventional coupling of human animals of either or both sexes usually in threes, but sometimes in ambitious pairs. I am unwilling to describe the configuration here, but Google should point you to an explicit How-To website.

Soap Sausage

Soap Sausage is anything served up for a meal in any particular popular evening television show. These delicacies serve 3 purposes.
1) To provide something to be thrown in an argument
2) To be a backdrop for a date that doesn't happen(ie, dater spends hours preparing said meal for datee, burning the house down in the process, or at least causing GBH to some poor passer by), and
3) To be on a fork midway between plate and mouth when the argument in scenario 1) breaks out in a public place.

Speaking of trouble, what is a Speke Lexden?

Ah, my dear, you are showing your age. A Speke Lexden is simply a dictionary (including pronunctiations) of "modern" English - i.e. as it is spoke.

I was glancing through one of my wife's specialist magazines the other week and came across the term tipple peak. To be honest I'm not sure whether I mis-read the words but, if not, can anyone help?

You read correctly. I assume this is latest edition of 'Hot Toddy Monthly', the magazine for liqueur coffee connoiseurs. The tipple peak is the small bit of cream on the top of, say, an Irish Cream that ends up on your nose if you glug it down.

Now that you are enlightened, can anyone tell me the purpose of Kemsing Ringers?