De or het outdoorkleding?

The correct Dutch article is:

de outdoorkleding

Rule Words ending in -ing: almost always de. See the rule
Meaning (Dutch) functionele kleding, speciaal ontworpen voor buitenactiviteiten (wandelen, skiën, trekking) om bescherming te bieden tegen weersinvloeden zoals wind, regen en kou.

How to use outdoorkleding

the outdoorkledingde outdoorkleding
this outdoorkledingdeze outdoorkleding
that outdoorkledingdie outdoorkleding
our outdoorkledingonze outdoorkleding
your outdoorkledingjouw outdoorkleding
every outdoorkledingelke outdoorkleding
which outdoorkleding?welke outdoorkleding?
a big outdoorkleding / the big outdoorkledingeen grote outdoorkleding, de grote outdoorkleding

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