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

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

The other part of the equation — making sure graduates land good jobs — is more complicated. —Eleanor Pringle, Fortune, 16 Oct. 2025

As a result, Portland isn’t just synonymous with Nike and Columbia Sportswear, Laika now factors into that equation. —Jazz Tangcay, Variety, 15 Oct. 2025

Pair with Earthy Tones When decorating with red, considering companion colors is a crucial part of the equation. —Patricia Shannon, Better Homes & Gardens, 14 Oct. 2025

What’s happening now simply makes that old equation visible to everyone else. —Josiah Bates, Time, 14 Oct. 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