[n] the act of contaminating or polluting; including (either intentionally or accidentally) unwanted substances or factors
[n] the state of being polluted
[n] undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities
befoulment - (3 syllables), contamination - (5 syllables), defilement - (3 syllables)
\Pol*lu"tion\, n. [L. pollutio: cf. F. pollution.]
1. The act of polluting, or the state of being polluted (in any sense of the verb); defilement; uncleanness; impurity.
2. (Med.) The emission of semen, or sperm, at other times than in sexual intercourse. --Dunglison.