aspell-cs software package provides Czech dictionary for GNU Aspell, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install aspell-cs
aspell-cs is installed in your system.
Make ensure the aspell-cs package were installed using the commands given below,
$ sudo dpkg-query -l | grep aspell-cs *
You will get with aspell-cs package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Text Processing |
| Package | aspell-cs |
| Version | 0.51.0-1 |
| Description | Czech dictionary for GNU Aspell |
| Sub Section | Text |