In today’s paper I read:
Moisture and filth on the video detection camera’s lens can cause it not to detect cars…
I wondered why the speaker hadn’t used the more appropriate word for the context: dirt.
To me the word “filth” conveys something nastier than mere “dirt,” something not likely to make it to the lens of a camera suspended over traffic.
For example, a mother means three very different things when she says:
This room is messy.
This room is dirty.
This room is filthy!
With messy one pictures scattered clothing, books, and papers, but nothing a quick tidying can’t put to rights.
With dirty come images of dusty furniture, smeared windows, and perhaps dried mud clumps on the floor.
With filthy, however, the mind turns to fossilized half-eaten sandwiches, congealed pools of unrecognizable liquid, mysterious mattress stains, and ignored deposits from the family pet.
A look at the etymology of both dirt and filth reveals pretty nasty origins for both.
Dirt comes from an Old English word (dritan) meaning “to defecate.” In Middle English the noun drit meant “excrement.” The r and the i eventually traded places to form the modern spelling dirt. Linguists trace the word to the Latin word for “diarrhea.”
Filth goes back to the Old English word for foul which was related to the Old High German word for “rotten,” the Gothic word for “stinking,” and the Latin word from which “pus” derives.
I still think that what the traffic camera lens had on it was dirt.
By the way, that stuff in your garden where the flowers grow isn’t dirt. It’s soil.