Add sources for looking up synonyms and such other things.

[tmalsburg]

These sources could query local and remote databases.

[michael-heerdegen]

There is a package called "synonyms" from Drew Adams available from Melpa. Haven't tried it, I never use synonyms but always the word itself.

[michael-heerdegen]

I wonder which free dictionaries we could use for that purpose. I would be interested in being able to look up acronyms. There is "vera" in Debian, but it requires a dict server and client (the file is in .info format!).

[humitos]

I found this today (https://github.com/toroidal-code/synonymous.el) and it works good, but it's open a x-menu. So, maybe it's possible to take those options/suggestions and display them into the helm buffer.