The use of the word Portsmouth in a Face Pyjama is very similar to the use of the word Manchester above. It is used to describe something that is unutterably dull. Obviously a Portsmouth Kettle either needs a good polish or lacks charisma.

But what are Budgerigar Trousers?

Ah ha! You have come to the right man for that information. Back in the Dark Ages, circa 1958, I was heavily involved in the breeding of those delightful little creatures - budgerigars, that is, not trousers. Actually I would have taken on trousers but, in those days, it was nearly impossible to get the zips mated. However, I digress.
The main aim of breeders at that time was to produce a bird which would 'drop it's daks' only for the right mate; it was considered that this would enable the use of multi-species aviaries without the risk of any cross-breed infections. To this end many, many experiments were undertaken and, sadly, in the interest of science, many birds perished. Eventually, being a leading light in this field, I was successful - to a degree anyway. Regrettably, whilst the finished product looked fine and theoretically should have worked, it didn't. It turned out that the male budgies were only 'turned on' when the female produced with the new genes was deceased. So, effectively, the breed died out after only one generation. It became obvious that, instead of producing a budgies gene rouser, I had inadvertently come up with a budgie rigor rouser. This was a spectacular failure which, to my chagrin, has gone down in the annals of the bird breeding community as a 'cheap and seedy' endeavour. Unfortunately it was also picked up by the popular press (in particular the "Parrot Breeders' Bible.") So, with it's wide circulation - and numerous typographical errors - the term which they coined has now entered the common vernacular. I'm sure that most of you would know the phrase (although some are more protected than others) which both sexes use in the pub when a particularly attractive specimen of the opposite sex is sighted wearing a well fitting pair of jeans?
Basically it means that s/he wouldn't be interested in you even if you were dead!

Leaving wild life to itself these days I am now more involved in the 'meaning of everything'. So when I came across an articulated case the other day, I was rather intrigued. Something to do with the law? A strange and mobile computer container? The title of a detective novel? Anybody know?

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?