Continuing the discussion from Amen [alternative to "amiina"]:
Regarding your ‘pinning down what words are authentically part of a language is a slippery slope’ comment, my question to you is: what’s the point of pointing out the source of the loanword in a dictionary then?
Hi Christy! Great question and one that puts me and other dictionary makers’ feet to the fire! 
I don’t think that I myself ever really formally though this one through even when we started writing the dictionary! With that said, here’s some thoughts…
I think that sometimes the origins of loanwords are listed as part of a larger goal to help people see how languages of a region or the world relate to one another. This in turn can be used to inform our understanding of historical events, people, and processes.
From a narrower perspective, the origin of loanwords can potentially help users better understand why certain words have different connotations or are more often heard coming certain kinds of people in certain kinds of contexts.
In turn, both of them can help dictionary users make informed choices on what words they personally want to use to express themselves, make themselves understood, etc.
And this can, of course, mean avoiding/embracing/being neutral about so-called “loanwords” or just wanting more information and options and posting in a Forum for others to try to offer their two cents I ni ce!