swampiest
/ˈswɒmpɪɛst/Definitions
1. adjective
most swampy; characterized by the most swamps, marshes, or wetlands
“After hiking through the swampiest part of the forest, we reached the riverbank.”
2. adverb
to the greatest degree or extent, of swamps, marshes, or wetlands
“This area is swampiest near the coast where the sea water has flooded the land.”