[scribus] What is Glyphenstauchung?

[Rolf-Werner Eilert]

In the style managing dialog, I find Glyphenstauchung (sorry, don't know 
what it is in English locale) and some values the meaning of which isn't 
clear to me. On the font tab, I find Horizontal Scaling - this seems to 
be a different thing though.

Can somebody here explain me what that is - or point me to a wiki page 
or link that can enlighten me?

Thanks so much!

Rolf