Dingy
Part of speech: adjective
Definition: drab; shabby; dirty; squalid
Impure
Part of speech: verb
Definition: To defile; to [pollute].
Part of speech: adjective
Definition: Not pure; not clean; dirty; foul; filthy; containing something which is unclean or unwholesome; mixed or impregnated extraneous substances; adulterated; as, impure water or air; impure drugs, food, etc.Defiled by sin or guilt; unholy; unhallowed; -- said of persons or things.Unchaste; lewd; unclean; obscene; as, impure language or ideas.
Example sentence: Free speech is not to be regulated like diseased cattle and impure butter. The audience that hissed yesterday may applaud today, even for the same performance.