noun Physical contamination, now especially the contamination of the environment by harmful substances, or by disruptive levels of noise, light etc. .mw-parser-output .defdate{font-size:smaller}
Pollution levels are almost always higher in cities rather than the countryside, what with the cars, industry and so on.
noun Something that pollutes; a pollutant.
noun The desecration of something holy or sacred; defilement, profanation.
noun The ejaculation of semen outside of sexual intercourse, especially a nocturnal emission.
noun Moral or spiritual corruption; impurity, degradation, defilement.