gaseous compound that results from the high temperatures in internal combustion engines. which in rum causes atmospheric nitrogen to combine with oxygen. Nitrogen oxide (N ) is one of the major components of acid rain.
Merriam-Webster Online Dictionary
nitrogen oxide (noun) any of several oxides of nitrogen most of which are produced in combustion and are considered to be atmospheric pollutants as
a) - nitric oxide
b) - nitrogen dioxide
c) - nitrous oxide
nitrogen oxide (Wikipedia)
Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds: