Wight is pronounced "white". Wight can be found as "wiht". I have heard people pronounce this as "wit". Is this mispronounced or for example dutch white = WIT?
Wight and Wiht is white? - English Language & Usage Stack Exchange
And there's the viral video by Shaun Bloodworth, which is said to have been responsible for saving Ernest Wight from closure. In another ten-year-old video the term is used yet again but by a different filmmaker: “Cliff works as a master scissors putter-togetherer.
The distinction between abbreviations (e.g. I.o.W = Isle of Wight) and contractions (e.g. Dr = Doctor, where the first and last letters are retained) is a useful one, but has been eroded in the 20c. by a widespread tendency to abandon the use of full points altogether for both types.
It is a matter of convention. The same goes for many other geologic or hydrologic features: the Leyte Gulf but the Gulf of Mexico, Loch Lomond but Alemoor Loch, the Isle of Wight but Portsea Island. That said, Nnn River is the far more prevalent form in the U.S.; it would be quite rare to hear of the River Missouri or the River Columbia in prose.
The earliest attestation of those noun variants is for 'jipper', in 1886, when it appears in William Henry Long's A dictionary of the Isle of Wight dialect: Jipper. Juice, or syrup of anything, as of a pudding or pie. "Mind what thee bist dooen wi' the skimmer, thee'st lat all the jipper out of the pudden."
Another learned wight, determined not to be left behind hand, very consequentially gave the three R's, that is, said he, ' Reading, Riting, and Rithmetic. And similarly, in yet another rendition of the anecdote in The Literary Gazette, and Journal of Belles Lettres, Arts, Politics, etc. (): Anecdotes by Philarchon.
In modern everyday use 'Isle' tends to be included in the name by which the place is known, such as the ones you mention plus the Isle of Skye, Isle of Mull, Isle of Wight etc.
According to Wright, the verb was common across Ireland, Yorkshire, Wiltshire, Gloucester-shire, Wales, the West Country, and the Isle of Wight. Transferred to a vertical plane, it means ’to bounce’, as in the description of the first football play in Cardiff (1873–4):