equation

noun

equa·​tion i-ˈkwā-zhən 

also -shən

1

a

: the act or process of equating

b(1)

: an element affecting a process : factor

(2)

: a complex of variable factors

c

: a state of being equated

specifically : a state of close association or identification

To bring governmental enterprises and payment for them into immediate equation …

—R. G. Tugwell

2

a

: a usually formal statement of the equality or equivalence of mathematical or logical expressions

b

: an expression representing a chemical reaction quantitatively by means of chemical symbols

Examples of equation in a Sentence

the equation of material wealth with happiness

Recent Examples on the Web

Samsung Is All In on Silicon Carbon The batteries inside the Samsung Galaxy Z Flip 8, Z Fold 8, and Z Fold 8 Ultra all benefit from the energy-storage equation. — Eric Zeman, PC Magazine, 22 July 2026

Designing for rescue changes the equation Designing a satellite with a standardized fixture to grab onto and navigation markers to help the servicer line up can cut down on uncertainty. — Wanjiku Chebet Kanjumba, The Conversation, 22 July 2026

Another part of the comfort equation is the brand’s RearFoot PureGEL technology, which is designed to be 65 percent softer than the usual gel used in footwear. — Tanya Sharma, PEOPLE, 22 July 2026

What This Means For Modern Buyers For today’s acquirers, this changes the equation. — Bhaskar Ahuja, Forbes.com, 22 July 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing equation

• characteristic equation
• cubic equation
• differential equation
• Diophantine equation
• enter (into) the equation
• equation of time
• linear equation
• parametric equation
• partial differential equation
• personal equation
• quadratic equation
• Schrödinger equation
• simple equation
• wave equation

Rhymes for equation

• abrasion
• caucasian
• eurasian
• evasion
• invasion
• occasion
• persuasion
• asian
• suasion
• athanasian

Kids Definition

equation

noun

equa·​tion i-ˈkwā-zhən 

also -shən

1

: the act or process of equating : the state of being equated

2

a

: a statement of the equality of two mathematical expressions

b

: an expression involving chemical symbols for a chemical reaction

Medical Definition

equation

noun

equa·​tion

i-ˈkwā-zhən also -shən

: an expression representing a chemical reaction quantitatively by means of chemical symbols