This is the 2646th most frequent Swedish word.
schweiziska
"Schweiziska" in English means "Swiss" (relating to Switzerland or the Swiss German language).
Here, 'schweiziska' refers to the Swiss language, specifically likely Swiss German in daily conversation.
Jag lärde mig schweiziska när jag bodde i Zürich.
I learned Swiss while living in Zürich.
Here, 'schweiziska' is used as an adjective describing something of Swiss origin, in this case, a watch.
Den schweiziska klockan var verkligen imponerande.
The Swiss watch was truly impressive.
In this usage, 'schweizisk' is the adjective form related to Swiss items, here describing chocolate.