The Channel is the English Channel, the stretch of water which separates southern England from northern France.
Portsmouth is one of the Channel Ports, situated on the coast of Hampshire. For many centuries, it was one of the principal dockyards of the Royal Navy, alongside Chatham, Deptford, Plymouth, and Woolwich.
Spithead is an area of the Solent, the stretch of water between the Hampshire coast and the Isle of Wight. It is what is known as a roadstead (a place outside of a harbour where a ship is able to lie at anchor).
The Commissioner's refers to the administrative quarters of the individual who represented the British Government in various parts of the British Empire. Today, the chief representatives of the UK in Commonwealth countries are known as High Commissioners.
Gibraltar (sometimes referred to as the Rock of Gibraltar) is situated at the southern tip of the Iberian Peninsula, at the entrance to the Mediterranean. It came under British rule in 1713, and remains one of fourteen British Overseas Territories. Historically, it has been an important Royal Navy Base.
Speculation is a gambling card game which first became popular towards the end of the 18th century and remained so for about a hundred years.
Thornton Lacey (one of the parishes destined for Edmund Bertram once he is ordained) is a fictional location. However its bi-partite structure is very characteristic of many English village names. Indeed, there are several villages in England which have Thornton as their first part, including Thornton Curtis, Thornton Hough and Thornton Steward. There are also English villages named Lacey Green and Mansel Lacy.
Other intriguingly-named English villages which follow the same bi-partite pattern are: Ainderby Quernhow; Ewyas Harold; Farleigh Wallop; Maiden Bradley; Moreton Pinkney; Newton Bromswold; Swaffham Bulbeck; and Weare Giffard.