Definitions

Shibbolet: is a word that identifies someone as a member of linguistic group. It is something that gives you away.

Synchronic: Linguistics. [tr. F. synchronique (F. de Saussure a 1913, in Cours de linguistique générale (1916) iii. 117).] Pertaining to or designating a method of linguistic study concerned with the state of a language at one time, past or present; descriptive, as opposed to historical or diachronic. Also transf. in Anthropology, etc. (from O.E.D)

(http://dictionary.oed.com/cgi/entry/50245273?single=1&query_type=word&queryword=synchronic&first=1&max_to_show=10)

Unattested: means that we have no record.

Scare quotes: is a term for a particular use of quotation marks. In this application the quotation marks are placed around a single word or phrase, and they indicate that the word or phrase does not signify its literal or conventional meaning but should be interpreted with one of the alternative meanings described below. In contradiction to the usual typographic purpose of quotation marks, the enclosed word(s) may not necessarily be quoted from another source. (wikipedia)

Layperson: they have ideas about a language and their ideas are sometimes absurd. They are not experts. They know about the language but not in a perfect way.

A nonstandard dialect of a language is a dialect of a language that does not have the institutional support or sanction that a standardized dialect has. A nonstandard dialect has its own vocabulary and an internally consistent grammar and syntax. A nonstandard dialect, like a standard dialect, may be spoken using a variety of accents. A nonstandard dialect may even have its own written form.

(http://www.nationmaster.com/encyclopedia/Nonstandard-dialect)

Constraints: A constraint is a restriction on the degree of freedom you have in providing a solution. Constraints are effectively global requirements, such as limited development resources or a decision by senior management that restricts the way you develop a system. Constraints can be economic, political, technical, or environmental and pertain to your project resources, schedule, target environment, or to the system itself.

(http://www.agilemodeling.com/artifacts/constraint.htm)

Embedding: The action of embedding a (partial) sentence in a larger sentence; an instance of this.

(http://dictionary.oed.com/cgi/entry/00292452?query_type=word&queryword=embedding&first=1&max_to_show=10&sort_type=alpha&result_place=2&search_id=qlCT-SOspal-16878&hilite=002924529)

Transition: The passage from an earlier to a later stage of development or formation.

(http://dictionary.oed.com/cgi/entry/50256294?query_type=word&queryword=transition&first=1&max_to_show=10&sort_type=alpha&result_place=1&search_id=qlCT-x0qgFJ-16916&hilite=50256294)

Divergence: The action of diverging: moving off in different directions from the same point (called the point of divergence), so that the intervening distance continually increases. The opposite of convergence.

(http://dictionary.oed.com/cgi/entry/50067756?single=1&query_type=word&queryword=DIVERGENCE&first=1&max_to_show=10)

Interlanguage: Linguistics. A linguistic system typically developed by a student before acquiring fluency in a foreign language, and containing elements of both his or her native tongue and of the target language.

(http://dictionary.oed.com/cgi/entry/50119176?query_type=word&queryword=interlanguage&first=1&max_to_show=10&sort_type=alpha&result_place=1&search_id=1KJS-DaBwFQ-1811&hilite=50119176)

Vernacular: 1. That writes, uses, or speaks the native or indigenous language of a country or district. 2. Of a language or dialect: That is naturally spoken by the people of a particular country or district; native, indigenous.
(http://dictionary.oed.com/cgi/entry/50276520?single=1&query_type=word&queryword=vernacular&first=1&max_to_show=10)