Use 'unwashed' to vividly describe something dirty, as if you can see the dirt or filth on it. The dog's once white fur was now an unwashed, muddy brown.
Pro Tip 2/3
Neglect Indication
'Unwashed' suggests neglect or lack of care, especially for personal items or appearance. Her unwashed appearance hinted at the rough week she'd endured.
Pro Tip 3/3
Physical State
Use 'unwashed' for tangible items or people, not for abstract concepts. The sink was piled with unwashed plates from the party.