If something is meshier, it has more mesh or is made of more mesh.
Meshier can make people think of things that are more tangled or complicated.
Examples:
The new fabric is meshier than the old one.
This net is getting meshier and meshier.
The water is getting meshier as more fish swim in it.
My hair gets meshier when I don't brush it.
The mystery got meshier and meshier as we found more clues.
The more we talked, the story got meshier and meshier.