equation

American  

[ih-kwey-zhuhn, -shuhn] / ɪˈkweɪ ʒən, -ʃən /

noun

1. the act of equating or making equal; equalization.

   the symbolic equation of darkness with death.

2. equally balanced state; equilibrium.

3. Mathematics. an expression or a proposition, often algebraic, asserting the equality of two quantities.

4. Also called chemical equation.  Chemistry. a symbolic representation showing the kind and amount of the starting materials and products of a reaction.

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equation British  

/ ɪˈkweɪʒən, -ʃən /

noun

1. a mathematical statement that two expressions are equal: it is either an identity in which the variables can assume any value, or a conditional equation in which the variables have only certain values (roots)

2. the act of regarding as equal; equating

3. the act of making equal or balanced; equalization

4. a situation, esp one regarded as having a number of conflicting elements

   what you want doesn't come into the equation

5. the state of being equal, equivalent, or equally balanced

6. a situation or problem in which a number of factors need to be considered

7. See chemical equation

8. astronomy See personal equation

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equation Scientific  

/ ĭ-kwā′zhən /

1. Mathematics A written statement indicating the equality of two expressions. It consists of a sequence of symbols that is split into left and right sides joined by an equal sign. For example, 2 + 3 + 5 = 10 is an equation.

2. Chemistry A written representation of a chemical reaction, in which the symbols and amounts of the reactants are separated from those of the products by an equal sign, arrow, or a set of opposing arrows. For example, Ca(OH) ₂ + H ₂ SO ₄ = CaSO ₄ + 2H ₂ O, is an equation.

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Other Word Forms

• equational adjective
• equationally adverb
• nonequation noun

Etymology

Origin of equation

1350–1400; Middle English < Latin aequātiōn- (stem of aequātiō ) an equalizing. See equate, -ion

Example Sentences

Now determining whether I can afford something has shifted from a guess every time I click “buy” to a math equation I actually know how to solve.

From MarketWatch • Mar. 31, 2026

"I think that equation is the most difficult one that Pakistan is going to have to think through if its current plans don't work out."

From BBC • Mar. 30, 2026

The agency last week agreed to release emergency stocks but said Friday that the demand side is also a crucial part of the energy security equation.

From The Wall Street Journal • Mar. 22, 2026

But a third factor is entangled in this equation: access to food and water, both of which become more difficult to acquire as wars spread and global temperatures ratchet upward.

From Salon • Mar. 17, 2026

Beside the fifth: You forgot to balance the equation.

From "The Sea in Winter" by Christine Day