English▸ noun [mass noun] extremely small pieces or particles of plastic resulting from the disposal or breakdown of plastic products and constituting debris or pollution, especially in a marine environment:
we analyse nanoplastic in all kinds of soils and composts
[as modifier] nanoplastic particles enter the food chain through plankton
[count noun] there is a serious risk of nanoplastics moving up the food chain, from filter feeder, to fish, to human.