Translation:We are putting the trash in the trash can.
- het vuilnis = the garbage
- de bak = the container, the bin
- het vuil = the dirt
-nis is a suffix, not a well known one, I don't know what it means or how it modifies meaning but it is used in e.g.
- de gevangenis = the prison (an interesting word now that I think of it: vangen = to catch/to capture, gevangen = caught/captured, also the outdated het gevang has the same meaning as de gevangenis)
- de gevangene = the prisoner
- de kennis = the knowledge
- kennen = to know
- de duisternis = the darkness (duister is usually an adjective, meaning dark, sinister)
- de betekenis = the meaning
- de hindernis = the obstacle
-nis in Dutch is -ness in English.
"Vuil" is a cognate of "foul".
So, it would be kind of "foulnessbox" or "foulnessbin".