PM2.5
noun/ˌpiː em ˌtuː pɔɪnt ˈfaɪv/
/ˌpiː em ˌtuː pɔɪnt ˈfaɪv/
[uncountable]- tiny pieces of a substance less than 2.5 micrometres long or wide that can be breathed in (the abbreviation for ‘particulate matter 2.5’)
- The main danger lies with PM2.5, tiny soot particles with a diameter of 2.5 microns.
Definitions on the go
Look up any word in the dictionary offline, anytime, anywhere with the Oxford Advanced Learner’s Dictionary app.
Check pronunciation:
PM2.5