Inertia

How to spell inertia

7 letters · 3 syllables

How to pronounce inertia

Say the part in capitals loudest.

What does inertia mean?

1. nounA tendency to remain unchanged, inactive, or unwilling to take action.
2. nounThe property by which matter continues in its existing state of rest or motion unless acted on by an external force.

Inertia in a sentence

• Bureaucratic inertia delayed the project for months.

• A heavier flywheel has greater inertia and is harder to start spinning.

• After the holidays it took real effort to overcome the inertia and return to work.

• The seatbelt counters the inertia that throws a passenger forward when a car stops suddenly.

Where does inertia come from?

Language of origin: Latin

The word comes from the Latin inertia, meaning 'idleness', 'lack of skill', or 'sluggishness'. That noun was built from iners, which combined in- 'not' with ars, artis 'art, skill', so the original sense literally described someone without art, that is, lazy or incompetent. English borrowed it in the early 1600s in that general sense of laziness and inactivity. The physicist Johannes Kepler and later Isaac Newton gave it its precise scientific meaning, naming the property by which matter resists any change to its state of motion or rest. Knowing that the middle holds the Latin root for 'art' or 'skill' (the same family behind the words 'art' and 'inert') helps explain the spelling: it is in-ert-ia, not the '-sha' sound the ear suggests.

How the word is built

• in- (not)
• -ert- (from Latin ars, artis: skill, art)
• -ia (noun suffix)