Name those top five dictionaries!
My response to a request from a university librarian who is a friend, to name my top five choices for best Chinese dictionaries in print to support a program that teaches Chinese medicine students how to read the medical classics (but not modern Chinese) as part of the curriculum (pardon the typos since I just went swimming in the sea, and it’s barely above freezing both in and out of the water)
For classical dictionaries, the main resource, which is absolutely outstanding, is Paul Kroll's dictionary:
It's available in paperback for fairly cheap now and completely revolutionized the field a few years ago when it first came out.
Before that, the ONLY half-way decent dictionary from classical Chinese into English was Mathews:
You can find that one really cheap used.
I would definitely recommend that you carry both of these. In addition, there is an incredibly useful French dictionary but I have no idea what a hard copy would cost or how you feel about carrying a French to classical Chinese dictionary.
Both Kroll and the Grand Ricci are available as paid add-ons to Pleco, which is free in and of itself. I used to require my students to buy the Kroll either as a hard copy or paid add-on for Pleco, which is what 99% of my students did. If you just use the regular Pleco app or Wenlin and similar translation software, you end up with very misleading information because those are primarily modern Chinese dictionaries that don't make too much sense for classical literature.
That is it for classical Chinese dictionaries. In addition, I would get Wiseman and Feng's Practical Dictionary of Classical Chinese.
This is an awesome resource (also available as a paid add-on for Pleco, by the way) and far more than just a dictionary. For any new acquisitions, I would recommend that you get a catalogue from Redwing Books and order through them because they are good people and deserve to be supported.
And for #5, I would get a Chinese-Chinese dictionary, I hate to say it. I would strongly suggest you get the 漢語大辭典 Hanyu Da Cidian (Great Dictionary of Chinese). But of course that one really depends on your budget since the number of students able to use a resource like that is probably pretty small.
Lastly, I am looking at my desk and resources I use all the time: I have a 中醫大辭典 (Great Dictionary of Chinese Medicine) Zhongyi da cidian. That one would be a great resource. It's Chinese-Chinese but fairly easy to use (Pinyin index in the back) and has short definitions with a lot of classical citations. And it's not a resource that is on the internet, as far as I know.