American Dictionary
Define dictionary terms easily — search for "example", "dictionary", "language", or "word" in our powerful online English dictionary.
Define dictionary terms easily in our powerful online English dictionary.
Searching for...
No matching words found
Try a different search term or browse the dictionary
particulate matter: the mixture of solid particles and liquid droplets in the air
PM can be naturally occurring or human made.
Fine particulate matter (PM2.5) is an air pollutant that is a concern for people's health when levels in air are high.
