Dictionnaries used are the same as the one used by Thunderbird, or OpenOffice (not sure that the last 3.1 version uses always it).
You can copy it in Dictionnaries folder under K-Meleon, or change the dictionnary path and choose OpenOffice one, and you'll probably then have more dictionnaries the same time.
A+
Mozilla/5.0 (x11; U; Linux x86_64; fr-FR; rv:38.0) Gecko/20100101 Ubuntu/12.04 K-Meleon/76.0
Web:
http://jujuland.pagesperso-orange.fr/
Mail : alain [dot] aupeix [at] wanadoo [dot] fr
Ubuntu 12.04 - Gramps 3.4.9 - Harbour 3.2.0 - Hwgui 2.20-3 - K-Meleon 76.0 rc