What does filth mean?
Filth is an uncountable noun referring to disgusting dirt — the grime, refuse, or foul matter that accumulates when something is left uncleaned. By extension, it describes anything considered morally repugnant, especially obscene language, imagery, or entertainment, as when critics denounce a work as mere 'filth'. The word carries strong connotations of disgust and contamination, making it more visceral than neutral terms like 'dirt'; calling something filth is always a condemnation, whether of a squalid room or of someone's conduct. Derived forms include the very common adjective 'filthy', which also serves as an intensifier in phrases like 'filthy rich'. Tracing back to Old English, where it meant corruption or putrefaction, the word is related to 'foul' and has retained its power to shock for over a millennium. It remains a vivid, forceful choice for describing both physical squalor and perceived moral degradation.
Disgusting dirt or foul matter; extreme uncleanliness.
"She scrubbed the kitchen until every trace of filth was gone."
Uncountable; takes singular agreement and has no standard plural.
Obscene, corrupt, or morally offensive language, publications, or behaviour.
"Censors condemned the magazine as sheer filth."
Often hyperbolic or judgemental in tone.
'Filth' is an uncountable mass noun and has no standard plural form; quantities are expressed periphrastically, e.g. 'piles of filth'.
"Piles of filth had collected behind the bins."
'Filth' and 'foul' are family — both trace back over a thousand years to an Old English word for something rotten and putrid.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of filth
Filth descends from Old English fȳlþ, formed from the adjective fūl, meaning foul or rotten, which itself traces back to the Proto-Germanic root underlying the modern word 'foul'. The original sense involved putrefaction and moral as well as physical corruption, and the word has been used for obscene or immoral matter since its earliest recorded history. It is thus a genuinely ancient English formation rather than a borrowing, with cognates in other Germanic languages such as related forms in Dutch and German built on the same root.
Related word forms
How filth is actually used
Uncountable noun with no common plural form. In its moral sense ('filth' as pornography or obscenity), it carries a strongly judgemental, often hyperbolic tone typical of complaints or censorship rhetoric. The adjective 'filthy' is far more frequent than the noun in everyday speech.
Easily confused with filth
'Fifth' denotes the ordinal number 5th, while 'filth' means disgusting dirt or obscenity; they differ only slightly in sound.