in a way that creates a wide piece of something

the meat was too thickly cut and impossible to chew

thickly sliced bread

in a closely compacted or crowded manner

a thickly populated area

thickly forested hillsides

in a stupid manner

"Isn't he a politician?" I say rather thickly

with a hoarse or husky voice; indistinctly

"You woke me up," he said thickly