propulsion
noun
Propulsion — the force that drives something forward through space
Definition
The act of propelling
In depth
Propulsion is the act of propelling, the application of force that moves an object forward, whether through mechanical engines, muscular exertion, or natural processes. The word names not merely motion itself but its driving cause, the power source behind any forward thrust.
Origin
The word descends from Latin propulsus, the past participle of propellere, to drive forward, formed from pro- (forward) and pellere (to drive or push) — the same root behind 'expel' and 'compel.' That sense of forceful, deliberate forward driving remains the word's essential image, whether applied to rockets or to the restless inner momentum of a human life.
Usage examples
"Rocket propulsion relies on the simple, violent physics of expelling mass in one direction to move in the other."
"The squid's propulsion through water, achieved by forcefully expelling jets of fluid, remains remarkably efficient."
"He found, somewhat to his surprise, that grief itself could become a strange kind of propulsion, driving him toward work he had long avoided."
How to use it
Propulsion is precise, often technical vocabulary at home in physics, engineering, and biology, describing the mechanism behind forward motion. In figurative use, it can powerfully describe the underlying drive behind a person's actions or ambitions.
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