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

Explanation

In an equation, the quantities on both sides of the equal sign are equal. That's the mathematical meaning of equation, but equation can also be used in any number of situations, challenges, or efforts to solve a problem. The "equa" at the beginning of equation will be familiar from other words such as "equal," "equality," and "equate." All of these words have to do with making things balance out. An equation is a statement of the equality of two quantities. If that equation is not a mathematical one but rather, say, an interpersonal one, it's still a situation in which you might try to make the two sides equal. For example, taking marriage out of the equation might make it easier for two people to decide to stay together for a while.

Example Sentences

Lower prices improve the housing cost equation for would-be buyers—at a potential psychological cost.

From Barron's • May 5, 2026

Unwarranted beliefs—those without basis in reality, like astrology—are dangerous on either side of the equation.

From Slate • May 5, 2026

"If they are part of the equation, it will only be because television companies want them to provide the spectacular background, so that they can bring their pictures into millions of homes," he said.

From BBC • May 4, 2026

Add name, image and likeness opportunities and the transfer portal, and the equation changes further.

From The Wall Street Journal • May 1, 2026

Even though physicists quickly realized that Planck’s equation was right, they did not accept the quantum hypothesis.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife