Definitions
1.NounPhysical 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."
2.NounSomething that pollutes; a pollutant.
3.NounThe desecration of something holy or sacred; defilement, profanation.
4.NounThe ejaculation of semen outside of sexual intercourse, especially a nocturnal emission.
5.NounMoral or spiritual corruption; impurity, degradation, defilement.