I. adjective
also pro·pel·lent -ˈpe-lənt
Date: 1644
: capable of propelling
II. noun
also propellent
Date: 1814
: something that propels: as
a. : an explosive for propelling projectiles
b. : fuel plus oxidizer used by a rocket engine
c. : a gas kept under pressure in a bottle or can for expelling the contents when the pressure is released