In French, the other official language in Belgium, the word for friendship is amitié.
However, there are many other ways to express friendship in both languages depending on the context and nuance you want to convey. For example, you could use words like:
* Vrienden (Dutch) or Amis (French) for "friends"
* Kameraad (Dutch) or Camarade (French) for "comrade" or close friend
* Gezelligheid (Dutch) or Convivialité (French) for a warm and friendly atmosphere
* Liefde (Dutch) or Amour (French) for "love" in the context of a very close friendship
Ultimately, the best word to use depends on the specific situation and the meaning you want to convey.