Mirror to Appeal to Definition?

I see the danger of making logical mistake when following dictionary as a final authority, but I see also a mirror fallacy possibility. Actually I have already noticed that in certain public discussions.

Yes dictionaries (as any books) are always one step behind the actual living language and there is risks of certain insufficiency especially in short dictionaries, BUT why is it really wrong to use as you say “a definition of a term as evidence that term cannot have another meaning, expanded meaning, or even conflicting meaning" from a dictionary at least as part of an argument?

Arguments sometimes take shape of defining specific words. When both sides stick to their definitions, in my opinion comparison of those with few dictionaries make things clearer. They might find by looking in several dictionaries that both of them are right and STOP arguing about actual definitions. But there is also possibility of finding that one or both definitions are WRONG.

Lexicographers are actually ones who do "more" objective research of word usage and meanings, so when people argue dictionary can be wonderful tool of bringing some level of objectivity in conversation.

Both of your examples in your book shows poor judgment of not checking the quality of the source (and it really doesn't matter whether it is old dictionary or bad web site or unreliable news channel). The problem did NOT arise from using dictionary in argument. It came from using too old dictionary. So why is there a need for singling out dictionaries?

Even more when you say that dictionary does work when there is ignorance about the term, without mirror fallacy one can immediately start to argue that person's wrong definition is really other correct definition that is just not in the dictionary simply blaming opponent in appeal to definition. I have literally seen those conversations like

Peter: How did you like (insert band's name) new album?
John: Ok. Though I liked their jazz album bit better than their electronic dance music stuff.
Peter: What do you mean? This album was jazz.
John: Well they did not improvise, there was no swinging rhythm involved and they didn't use anything based on blues scales.
Peter: You are so close minded. Jazz is way of life, it is way of thinking, freedom... Jazz can be everything. Don't bring up dictionary definitions.

If there is this concept of appeal to definition that singles out dictionaries, shouldn't there also be a mirror fallacy that warns against irrational avoidance of dictionary definition?

Your points are well taken and yes, there are times when official definitions are ignored, which can be very problematic. For example, more recently, "racism" has been redefined as "including power," basically meaning that only white people can be racist. As a social psychologists that drives me nuts because racism is a term used in the social sciences and carefully defined for the purposes of research. But problematic isn't necessarily fallacious.

BUT why is it really wrong to use as you say “a definition of a term as evidence that term cannot have another meaning, expanded meaning, or even conflicting meaning" from a dictionary at least as part of an argument?

Because absence of evidence is not necessarily evidence of absence, in other words, if one dictionary leaves out a usage of the term, it does not mean that excluded usage isn't valid. The fallacy is in the assumption that your chosen dictionary is the ultimate authority on the word being defined. In terms of science, this would be like one person pointing to one study as a scientific fact. Of course, we need to look at other studies, better yet, meta-analyses which can give us a much more accurate picture. Dictionary use needs to be the same. Generally, this is not a problem but sometimes minor differences can have drastic effects on an argument.

So why is there a need for singling out dictionaries?

Because like scientific papers, if the definition is vital to the argument being made, it's a good idea to consult multiple sources... including encyclopedias and scientific papers where the term might have been operationalized.

If there is this concept of appeal to definition that singles out dictionaries, shouldn't there also be a mirror fallacy that warns against irrational avoidance of dictionary definition?

Perhaps there should be. Like I mentioned, I have been seeing this more and more. I am not sure how common it was in the past, but in our "post-truth" world people seem to be fine with making things up. But is this fallacious, or just a manipulation technique by the ones ignoring the dictionary definition? Those who buy into the made up definitions, are they being unreasonable or are they simply ignorant (not knowing the actual definition) or too trusting of the source? Maybe a fallacy should be created.

The fallacy is an appeal to "pictionary"...That is people who reason that words at like pictures , each can be painted however they need them to be to fit their argument.
Or, an appeal to bookwormagoguery ,, creating the illusion that some definitions can't be found in any place where definitions should be..