/ pəˈluːʃn; NAmE / noun [ U ]
1.
the process of making air, water, soil, etc. dirty; the state of being dirty :
air / water pollution
to reduce levels of environmental pollution
2.
substances that make air, water, soil, etc. dirty :
beaches covered with pollution
3.
noise / light ~ harmful or annoying levels of noise, or of artificial light at night
••
WORD ORIGIN
late Middle English : from Latin pollutio(n-) , from the verb polluere , based on the root of lutum mud.