De or het definitiecode?

The correct Dutch article is:

de definitiecode

Rule Words ending in -ode: always de. See the rule

How to use definitiecode

the definitiecodede definitiecode
this definitiecodedeze definitiecode
that definitiecodedie definitiecode
our definitiecodeonze definitiecode
your definitiecodejouw definitiecode
every definitiecodeelke definitiecode
which definitiecode?welke definitiecode?
a big definitiecode / the big definitiecodeeen grote definitiecode, de grote definitiecode