inertia
/ɪˈnɜːr.ʃə/
noun
Origin
Latin
iners — idle, sluggish, unskilled
Overview
Meaning Now
- A property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.
- A tendency to remain unchanged or to resist change; inactivity or sluggishness.
Literal older meaning
inactivity, sluggishness
Language path
Latin → English
Earliest form
inertia
Earliest period
17th century
Journey
The term was introduced into physics by Johannes Kepler in his 'Astronomia Nova' to describe the 'sluggishness' of planetary bodies, suggesting that matter has an inherent resistance to motion. It was later formalized in Isaac Newton's 'Philosophiae Naturalis Principia Mathematica' as the first law of motion.
Evolution
- Classical Latin
iners
“without skill; inactive”
Derived from 'in-' (not) + 'ars' (skill/art).
- Classical Latin
inertia
“idleness, ignorance”
Abstract noun derived from 'iners'.
- 17th Century
inertia
“physical resistance to change of motion”
Adopted into scientific English to define Newtonian mechanics.
Connections
Word parts
in-
prefix
not
art
root
skill
-ia
suffix
abstract noun marker
Related across languages
French
inertie
inertia
Explore next
Related to inertia
External references use DefinedTerm semantics.