from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An area that is for practical purposes an exclave, but does not meet the strict definition: an area that is not completely separated from the main part, but can only in practice be reached by passing through another area. For instance, a region of a country that is not connected by road to the main part of the country without passing through another country.
Sorry, no etymologies found.
As already mentioned in the post itself, the definition of what is a pene-exclave (and indeed a peninsula) hinges on how you define "almost" (as in, "almost an enclave" or "almost an island"), i.e. on the narrowness of the isthmus.