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

And all the possible dark wash denim cuts add another layer of interest to the equation — celebrities are wearing them in such creative ways, from funky flares to breezy wide-leg styles. —Nicol Natale, PEOPLE, 26 Nov. 2025

So theoretically, if an initiative used to cost $500,000 to implement with in-house resources, and machine learning can drop that cost down to $10,000, where does a $100,000 consulting fee fit in the equation? —Big Think, 26 Nov. 2025

The famous words coming from the stage are only part of the equation. —Jocelyn Noveck, Boston Herald, 26 Nov. 2025

Arike Ogunbowale’s future, Li Yueru’s status, and the direction of the frontcourt could all shift the equation. —Jalon Dixon, MSNBC Newsweek, 25 Nov. 2025

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