A metric unit of force equal to 10-9 newton (See below) or 0.1 millidyne. Nanonewtons measure the force of solar radiation and the tiny forces exerted within living cells
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}