This a plea for a definitions section in most OPs and wherever else useful or appropriate, whether formal or informal, or established or preliminary or tentative.

I'm persuaded that most who post to TPF neither know what a definition is nor what they're for. The evidence is many, many threads feeding on the energy of failed attempts to understand what the subject is, or what the terms mean. If the lack of that information is at first ignorance - the general condition of us all, always - and if that ignorance applied, or persisted in, in the face (even the possibility) of information is a definition of stupidity, then many posts and much that is posted is stupid. Sorry, but you just didn't know what you were talking about. The philosophy of religion forum the poster child of such efforts. Do you really suppose that you know what "god" means? Or that a) anyone else does, or b) that anyone else understands what you mean, or you what they mean?

Writing - let's call it speech - without understanding is in oh-so-many-ways a problem. It's akin to going into the woods to hunt with a rifle and just firing away randomly - maybe with the wrong rifle, even the wrong ammunition. And what could go wrong with that? Better to ask what could go right!

Language is a tool. What is a tool? A tool is something used to get something done; i.e., it is functional. That's the what-it-is-(for). How it works, what all the particular somethings are it's for, are separate (and sometimes of great interest) matters. By way of illustration, consider a wrench. A wrench is for tightening/loosening nuts and bolts. The wrench itself is not either the tightening or the loosening, or the nut or the bolt. Without these, it's not even a wrench.

A definition, then, is a statement as to the what-it-is-(for) of a particular piece of language. To extend a metaphor, definition allows for a tightening/loosening on the understanding of a subject matter. Without which, ultimately, it is not even any longer language (nor is there any subject matter).

A 9/16ths wrench is good for only 9/16ths nuts and bolts. Language is by no means so fixed. Language is like an adjustable wrench. But it has to be adjusted to be usefully used. I think - suspect - that many among us believe that definitions are found in dictionaries, and when found there, are final and incontrovertible. If that were so, then no discussion of anything would be needed or useful: one would need only consult the dictionary to resolve all questions. Clearly and obviously that is not quite what dictionaries are, or are for. They are themselves tools, with their own function and purpose.

Arguably every subject matter is bespoke, its language necessarily adjustable, with respect to its own concerns. The language in which that subject matter is expressed is therefore necessarily fitted. Sometimes the already-existing word is right. But often not. Sometimes new words are coined, like quark, and sometimes old words are redefined for present purpose, or made into terms of art understood to not mean what they mean in ordinary usage.

In any case, to achieve whatever the purpose of the use of language is, the language is qualified/quantified/defined. Failure means that the chance of achieving purpose is about the same as random shooting in the woods has of hitting any target.

There's an exception to all of this, falling under the generic name of brainstorming, which is the deliberate choice to operate without a net and even without a trapeze. You just jump out into space and hope for a soft landing. Not, generally, any way to discuss or argue anything, but instead a mistake about argumentation and the what, how, and what for of it.

Let us then resolve that, unless we're brainstorming, to achieve our purposes in discussion and argument that we establish, refine, adjust our tools to get our job done, that is, to provide definitions of our significant terms, even if they're merely waypoints useful for navigation, as points of departure, for our arguments. Absent the which, we're all just lost at sea.