De or het decadentisme?

The correct Dutch article is:

het decadentisme

Rule Words ending in -isme: almost always het. See the rule
Meaning (Dutch) (kunst) Neiging tot decadentie (in de kunst)

How to use decadentisme

the decadentismehet decadentisme
this decadentismedit decadentisme
that decadentismedat decadentisme
our decadentismeons decadentisme
your decadentismejouw decadentisme
every decadentismeelk decadentisme
which decadentisme?welk decadentisme?
a big decadentisme / the big decadentismeeen groot decadentisme, het grote decadentisme

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).