While nobody has ever calculated the average length of words, it’s commonly believed that the Welch language has the longest words:
Welsh town names are long words!
The Welsh is even longer than German, where they paste many words together into a single large word.
- Datenbanknen = database
- Gepäckaufbewahrungsschein = luggage check ticket
- Hoechsgeschwindigkeitsbegrenzung = maximum speed limit
But I have a new contended for the world’s longest words. The folks in Greenland folks speak Greenlandic, noted for super-long words, a real mouthful.
A sample of long words in Greenlandic
There are long words on their web sites too:
Long words on a Greenlandic web site
I suppose we will never know what language has the longest words, but don't rule out Greenlandic!