Very dirty or unclean; covered with dirt, grime, or disgusting material; also used to mean morally corrupt or offensive.
From Old English 'fylth' (unclean material or filth), with the '-y' suffix meaning 'full of' or 'having qualities of.' The word has roots in Proto-Germanic, and evolved to describe both physical and moral uncleanliness by the Middle Ages.
Across many languages, words for 'dirty' and 'morally corrupt' are almost identical—filthy, dirty, foul, unclean—suggesting that humans instinctively connect physical uncleanliness with moral wrongdoing. This pattern in language reveals deep psychology about how we perceive purity and corruption.
Complete word intelligence in one call. Free tier — 50 lookups/day.