I was wondering how could I remove one (wrongly inserted) entry/word from the ispell private-dictionary.
EDIT
after more digging i am still unable to delete entries from default dictionary, but I think the solution could be around buildhash program. The problem is to generate the list of entries to delete... i do not find a simple example.
On my cygwin install ispell is just a wrapper around aspell:
$ ispell
Ispell compatibility script for Aspell.
Usage: /usr/bin/ispell [options] -a|-l|-v[v]|-c|-e[1-4]|<file>
If that is true of your installation, then you need to look at aspell files. Try aspell dump config.
You should just be able to edit your personal dictionary file to remove the unwanted entry. The dictionary file is a text file, probably located at ~/.ispell_default, or ~/.ispell_[LANGUAGE], e.g. ~/.ispell_italian.
If you are using Emacs, it creates its own personal dictionary file under what Emacs sees as ~/.aspell.[LANGUAGE].pws. On Windows this happens to be: C:\Users\Username\AppData\Roaming\. This is probably just an effect of the environment Emacs runs the dictionary under. To edit it in Emacs, you can use the tilde *nix style path, as well as the absolute DOS style path.
Super late to the party but hopefully I can help someone else with this issue. If you look at the top of the emacs window it tells you what program emacs is using for the dictionary. In my case it read "prog: hunspell."
So all you have to do in that case is find the hunspell dictionary and edit (i.e., remove) the rogue word.
In my case, 'emacs ~/.hunspell_en_US', opened a text file where I located and removed the word I accidentally added.
来源：https://stackoverflow.com/questions/9889006/how-to-remove-an-entry-from-ispell-private-dictionary