Learn English – what does the phrase “a real word” mean

Twentyfive questions appear in the list of questions already asked on this forum that are similar to this question. Of those, 8 titles do not mention the "real word" phrase. The other 17 ask about a specific word, typically using a standard form: "Is X a real word". Additionally, I'm sure, many questions asked on this forum omit real and simply ask something to the effect of "Is X a word".

How can a question ask if a word is real without using the word as a word?

Detailed answers will be entertained. Explanations and examples of consensual approaches to designating some words as real, and others not, are of most value to me. How and when do, for example, scientific terms, become real terms? Nextmost in value are scales or systems of realness. For example, where do nonsense words, nonce-words, spurious words and neologisms fall on a scale of realness? within some system of realness? The central idea of both values (consensual approaches, and scales or systems) is to take the question beyond the realm of personal opinion as much as possible.

Any answers will be greatly appreciated.

Edit: It has been suggested that this question duplicates a question asking when a word becomes a word. This question differs markedly:

1. Temporal considerations ("when") are secondary, if relevant at all.
2. This question does not use a self-referential definition of 'word', unlike the suggested duplicate, which verges on incoherence by asking when a word becomes a word. But we all know what that question is meant to ask…or do we?
3. While I'm sincere in saying any answers to my question are appreciated, certainly no answer solely or primarily referencing appearance in a dictionary will be accepted (in the constrained sense of 'accepted' used on this forum). No self-respecting dictionary will define 'word' in a primary sense as dependent on dictionary inclusion. For example, the primary definition of 'word, n.' in the OED is "I. Speech, utterance, verbal expression." This definition has no direct connection to appearance in one or more dictionaries.

Those specific considerations (and others along the same lines) aside, serious answers to my question would account for my mention of nonsense and nonce-words, et al. For example, the list of spurious words in the OED (compact edition): does the OED define 'spurious words' as 'unreal words'?

It seems to me that on a forum such as this, a working definition of "real word" would be sine qua non, and that self-defeating definitions such as reference to appearance in dictionaries which themselves define 'word' as something quite other than 'an entry in a dictionary or lexicon' would be rejected outright. Threshold elements in the working definition, on the other hand, might well be unavoidable: for example, "one or more occurrences of an utterance embued with communicative power" or some such gibberish might be construed as constituting part of a desirable answer to the question of what the phrase "real word" means.

Similarly, the assertion that what constitutes a "real word" is arbitrary is a non-answer. We all understand something when we encounter the phrase, and there is more commonality than not in our somewhat various understandings.