# binomial

/baɪˈnoʊmiəɫ/ (US) · /baɪnˈəʊmɪəl/ (UK)

Source: https://englishreference.com/word/binomial
Updated: 2026-08-27

## Senses

### 1. mathematics

noun · CEFR C1 · Technical

a mathematical expression that has two parts connected by a plus or minus sign.

For teachers: an algebraic expression consisting of the sum or difference of two terms.

- In your algebra homework, 'x + 5' is a simple binomial.
- The student struggled to expand the binomial to the third power using the standard formula.

### 2. biology

noun · CEFR C1 · Technical

a scientific name for a living thing that uses two words, like 'Homo sapiens'.

For teachers: a taxonomic name at the rank of species, consisting of a generic name and a specific epithet.

- Every plant has a formal binomial to help scientists identify it exactly.
- Linnaeus established the system of binomial nomenclature to provide a universal language for biological classification.

### 3. having two parts

adjective · CEFR C1 · Academic

consisting of two names, terms, or parts.

For teachers: composed of or relating to two names or terms; non-gradable.

- The researcher used a binomial system to categorize the survey results.
- The paper proposes a binomial classification model to distinguish between the two distinct types of chemical reactions observed.

### 4. statistics

adjective · CEFR C1 · Technical

relating to a type of math that predicts the chances of two possible results.

For teachers: relating to the binomial distribution, which models the number of successes in a fixed number of independent trials.

- We used a binomial test to see if the coin was fair.
- The binomial distribution is appropriate here because each trial has exactly two possible outcomes with a constant probability of success.

## Examples

- The expression x + 3 is a binomial.
- In algebra, students learn to multiply two binomials using the FOIL method to expand the equation.
- The binomial theorem provides a systematic way to expand any power of a binomial, which is essential for calculating probabilities in a series of independent events.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.