De or het avant-gardisme?

The correct Dutch article is:

het avant-gardisme

Rule Words ending in -isme: almost always het. See the rule
Meaning (Dutch) (kunst) moderne, vernieuwende, grensverleggende stroming in de kunst en de wetenschap

How to use avant-gardisme

the avant-gardismehet avant-gardisme
this avant-gardismedit avant-gardisme
that avant-gardismedat avant-gardisme
our avant-gardismeons avant-gardisme
your avant-gardismejouw avant-gardisme
every avant-gardismeelk avant-gardisme
which avant-gardisme?welk avant-gardisme?
a big avant-gardisme / the big avant-gardismeeen groot avant-gardisme, het grote avant-gardisme

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