pro·pel·lant
noun/prəˈpelənt/
/prəˈpelənt/
[countable, uncountable]- a gas that forces out the contents of an aerosol
喷射剂（如喷雾器中的压缩气体） - a thing or substance that propels something, for example the fuel that fires a rocket
推进剂（如发射火箭用的燃料）
Word Originmid 17th cent.: originally from Latin propellent- ‘driving ahead (of oneself)’, from the verb propellere, later from propel.