English
equilibrium
Equilibrium comes from Latin aequilībrium ‘a level or horizontal position, equilibrium’, from lībra ‘balance’, and perhaps ultimately from Proto-Indo-European *leyH- ‘to pour’.
- Proto-Indo-Europeanc. 4500–2500 BCE*leyH-1‘to pour’uncertain
- Proto-Italicc. 1500–700 BCE*līðrā2‘ingot’uncertain
- Latinc. 75 BCE–200 CElībra3‘balance’
- Latinc. 75 BCE–200 CEaequilībrium3‘a level or horizontal position, equilibrium’
- Englishearliest quotation 1733equilibrium3
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, Proto-Italic *līðrā
- 2 Wiktionary, Latin libra
- 3 Wiktionary, English equilibrium
- Earliest quotation in Wiktionary’s entry: 1733, Philip Miller, HYDROSTATICKS: “To Hydroſtaticks belong whatever relates to the Gravities and…”.
Lineage
- Proto-Indo-Europeanc. 4500–2500 BCE*leyH-Wiktionary, Proto-Italic *līðrā‘to pour’uncertain
- Proto-Italicc. 1500–700 BCE*līðrāWiktionary, Latin libra‘ingot’uncertain
- Latinc. 75 BCE–200 CElībraWiktionary, English equilibrium‘balance’
- Latinc. 75 BCE–200 CEaequilībriumWiktionary, English equilibrium‘a level or horizontal position, equilibrium’
- Englishearliest quotation 1733equilibriumWiktionary, English equilibrium. Earliest quotation in Wiktionary’s entry: 1733, Philip Miller, HYDROSTATICKS: “To Hydroſtaticks belong whatever relates to the Gravities and…”
Linked words
through Proto-Italic *līðrā ‘ingot’
through Latin lībra ‘balance’
level, deliberate, deliberation, lira, libra, deliberative, 8 more
Today it means
noun The condition of a system in which competing influences are balanced, resulting in no net change.
Sources
Sources: Wiktionary, “equilibrium”; the older steps come from the Wiktionary entries for Proto-Italic *līðrā, Latin libra. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.
Etymograph / Proto-Indo-European *leyH- / equilibrium