De or het smetvrij?

The correct Dutch article is:

de smetvrij

Rule Words ending in -ij and -erij: usually de. See the rule

How to use smetvrij

the smetvrijde smetvrij
this smetvrijdeze smetvrij
that smetvrijdie smetvrij
our smetvrijonze smetvrij
your smetvrijjouw smetvrij
every smetvrijelke smetvrij
which smetvrij?welke smetvrij?
a big smetvrij / the big smetvrijeen grote smetvrij, de grote smetvrij