I thought I knew this word. It could be a little boat, often a little boat that lives on a bigger boat and is used to back and forth from the shoreline. It can also mean a little bit drab, or perhaps not entirely clean. It also can mean a sort of grubby off-blond hair color … or a faded hair color.
It is in the same category as grunge or grungy — which is sort of like a softened version of HDR, but grainier and not as sharp. Also, things that are described as “chalky” frequently are also dingy.
So these two are both dingy pictures. They look a bit antique and the light is subtly striated. Who knew, right? Yet another definition for a term you won’t find in the dictionary.