scummy

adjectives

of the most contemptible kind
"abject cowardice"; "a low stunt to pull"; "a low-down sneak"; "his miserable treatment of his family"; "You miserable skunk!"; "a scummy rabble"; "a scurvy trick"
abject, low, low-down, miserable, scummy, scurvy
covered with scum
"the scummy surface of the polluted pond"
scummy
is derived from
scum
is similar to
soiled or likely to soil with dirt or grime
"dirty unswept sidewalks"; "a child in dirty overalls"; "dirty slums"; "piles of dirty dishes"; "put his dirty feet on the clean sheet"; "wore an unclean shirt"; "mining is a dirty job"; "Cinderella did the dirty work while her sisters preened themselves"
dirty, soiled, unclean