hunspell-fr-comprehensive software package provides French dictionary for hunspell (comprehensive version), you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install hunspell-fr-comprehensive
hunspell-fr-comprehensive is installed in your system.
Make ensure the hunspell-fr-comprehensive package were installed using the commands given below,
$ sudo dpkg-query -l | grep hunspell-fr-comprehensive *
You will get with hunspell-fr-comprehensive package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Text Processing |
| Package | hunspell-fr-comprehensive |
| Version | 1:5.7-1 |
| Description | French dictionary for hunspell (comprehensive version) |
| Sub Section | Text |