"Especially" is an adverb used to introduce a qualification. Eg "I like people, especially cheerful people."
Maxperson, I don't know what your field of endeavour is, nor your education and/or professional training.
But what you are saying here, assuming that it is sincere, suggests a lack of familiarity with how English dictionaries work, and also how English essay writing works.
An English dictionary is (or at least aspires to be) an account of the establshed usages of English speakers. A serious scholarly dictionary (like the OED) for this reason contains illustrations of usage, with dages, that illustrate the development of these patterns of usage and thus justify the dictionary-makers assertions about them.
When the dictionary says that literature means the As, and especially the As that are also Bs, it is telling us that the word "literature" is used to mean A, but also, and especially, is used to mean the As that are Bs. There would be no point to including that second element of the definition if, in fact, there was no such distinctive and typical pattern of usage. In this case, one doesn't need to refer to a dictionary to make the point - it's not an obsecure one. If someone says, for instance, that s/he studies literature, I think most of us would assume that cookbooks and railway guides and stereo installation instructions are not on the syllabus. (Contrast if she said that she studies communication, in which case those things might well be candidate objects of study.)
Another feature of dictionaries is that they play a normative as well as a descriptive role: that is, people look to them for guidance on how they should use words. But of course this guidance is nothing more than that - if it was, then usage would never change! And a standard feature of essay writing in Engllish is the coining of neologisms, or the use of common place words with nuanced or narrowed meaning, whether expressly stated by the author or implied in some fashion. For a well-known example of the former, consider the final (I think, from memory) chapter of Bertrand Russell's well-known book The Problems of Philosophy, where he explains why much of what is ordinary called knowledge is, according to him, not worthy of that label - rather, he calls it "probable opinion". Russell - who won a Nobel Prize for Literature - is not ignorant of the use or meaning of the English word "knowledge". His distinct approach to use of it is in service of his phisophical position.
Providing an example of implied narrowing or nuancing is something I'll leave to another post if anyone is interested, as it takes more time to set one out, and the examples that are occurring to me at the present may be a bit controversial from the point of view of board rules. But I think it's a pretty well-known phenomon.
Antyway, the upshot is that when I ask is roleplaying a literary endeavour, and make it clear by my follow-up discussion in the OP that I'm focusing on whether it is wordcraftp or something else that is the principal device in RPGing for establishing the key aesthetic properties and provoking emotional responses, it's completely pointless to respond by saying that there is a usage of "literary" according to which the answer is trivially "yes". Because that's very obviously not how I was using the word "literary" in the phrase "literary endeavour". (And that's before we even get to the point that it is the whole phrase, and not just its adjecitival component, that is central to the position I'm articulating in this thread.)
