Impulse

How to spell impulse

7 letters · 2 syllables

How to pronounce impulse

Say the part in capitals loudest.

What does impulse mean?

1. nounA sudden strong desire to act, often without careful thought.
2. nounA force or influence that drives something forward, including the physics quantity of force applied over time.

Impulse in a sentence

• She bought the dress on a sudden impulse and regretted it the next morning.

• The new funding gave the project the impulse it needed to launch.

• He fought the impulse to check his phone during the meeting.

• In physics, the impulse of a collision equals the change in momentum.

Where does impulse come from?

Language of origin: Latin

This word comes from the Latin impulsus, the past participle of impellere, which meant 'to drive on' or 'to push against'. That verb was built from the prefix in-, here meaning 'into' or 'towards', joined to pellere, meaning 'to drive, push or beat'. English took the word in the early 1600s, first in a fairly literal sense of a physical thrust or driving force, before it broadened to the familiar mental sense of a sudden urge that pushes us to act. The same pellere root drives a whole family of relatives, including 'compel', 'expel', 'propel' and 'repel', and even the medical 'pulse' that beats in your wrist. Remembering that hidden push helps with the spelling: it is im-pulse, never im-pluse, with the consonant cluster -ls- kept intact from the Latin.

How the word is built

• im- (from in-: into, towards)
• pulse (from pulsus: a driving, beating, from pellere 'to drive')