Phrase guide

magic number

noun · 8 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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No pronunciation record was provided for this word.

1

noun

Meaning 1

The number of neutrons or protons in nuclei which are required to fill the major quantum shells, and thus produce exceptionally stable nuclei: 2, 8, 20, 28, 50, 82 and 126.

Definition source: English Wiktionary via Wiktextract

Qualifier: nuclear physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

A metric used to determine a team's required performance to make the playoffs.

The sum of one and the wins by one team and losses by an opponent necessary for the team to ensure the opponent cannot catch it in the standings by the end of the regular season. In Major League Baseball, with a regular season of 162 games, the magic number M is calculated as M = 163 − W1 − L2, in which W1 is the leading team's current win total, and L2 is the opponent's current loss total. A magic number of 0 indicates that the trailing team cannot catch the leading team.

Definition source: English Wiktionary via Wiktextract

Topics: hobbies, lifestyle, sports

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

A metric used to determine a team's required performance to make the playoffs.

The lowest such number that assures a team a playoff berth.

Definition source: English Wiktionary via Wiktextract

Usage: broadly

Topics: hobbies, lifestyle, sports

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

A number which is manually entered into source code, rather than defined somewhere as a named constant; especially one which is arbitrary or lacks explanation.

Definition source: English Wiktionary via Wiktextract

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, sciences

Examples

  • We replaced the magic number 31 with a constant called MAX_DAYS_IN_MONTH.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

noun

Meaning 5

A sentinel value which cannot occur in normal use, typically used as a placeholder (e.g. a fictitious date such as 2000-02-32).

Definition source: English Wiktionary via Wiktextract

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

6

noun

Meaning 6

A hash code, such as those used by some webmail servers to keep track of sessions.

Definition source: English Wiktionary via Wiktextract

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

7

noun

Meaning 7

A number or pattern in a binary file that identifies the filetype.

Definition source: English Wiktionary via Wiktextract

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

8

noun

Meaning 8

the atomic number of an extra stable strongly bound atomic nucleus: 2, 8, 20, 28, 50, 82 or 126

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: atomic number

History

Etymology

No etymology was provided for this word.