prime meridian: meaning, definition, pronunciation and examples
C1Formal/Technical
Quick answer
What does “prime meridian” mean?
The meridian at 0° longitude, from which all other longitudes are measured.
Audio
Pronunciation
Definition
Meaning and Definition
The meridian at 0° longitude, from which all other longitudes are measured.
The reference line for measuring global time zones (Greenwich Mean Time) and establishing geographical coordinates on Earth. It represents the agreed-upon starting point for the longitudinal coordinate system.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or syntactic difference. However, the historical and cultural association is stronger in British English due to the Greenwich Meridian's location in London.
Connotations
In British English, there is a stronger sense of historical and scientific pride. In American English, it is more neutral geographical terminology.
Frequency
Similar frequency in technical contexts. Slightly higher incidental frequency in UK media/tourism.
Grammar
How to Use “prime meridian” in a Sentence
[The] prime meridian [verb e.g., runs, is located] [prepositional phrase][Subject] [is] [east/west] [of] the prime meridianVocabulary
Collocations
Examples
Examples of “prime meridian” in a Sentence
verb
British English
- The new mapping software primes the meridian coordinates automatically.
- The chart was meridianed, with the prime line set at Greenwich.
American English
- The system primes the meridian settings during calibration.
- They meridianed the plot based on the 1884 agreement.
adverb
British English
- The satellite was positioned prime-meridianally.
- (Extremely rare; not standard).
American English
- The coordinates were set prime-meridianally for the simulation.
- (Extremely rare; not standard).
adjective
British English
- The prime-meridian marker is a popular tourist photo spot in Greenwich.
- The observatory holds prime-meridian status.
American English
- We visited the prime-meridian monument.
- The prime-meridian agreement was historic.
Usage
Meaning in Context
Business
Rare, except in logistics, global scheduling, or GPS-related technology.
Academic
Common in geography, astronomy, history of science, and cartography texts.
Everyday
Very rare. Might be encountered in travel contexts or quizzes.
Technical
Standard term in geospatial sciences, navigation, surveying, and timekeeping.
Vocabulary
Synonyms of “prime meridian”
Strong
Neutral
Weak
Vocabulary
Antonyms of “prime meridian”
Watch out
Common Mistakes When Using “prime meridian”
- Pronouncing 'meridian' as /məˈraɪ.di.ən/ (like 'ride').
- Using 'prime meridian' without the definite article 'the'.
- Confusing it with the 'equator' (which is 0° latitude).
FAQ
Frequently Asked Questions
It was internationally agreed upon at the 1884 International Meridian Conference largely due to the widespread use of British nautical charts and the reputation of the Royal Observatory, Greenwich, for accurate star charts essential for navigation.
In practice, yes. The 'Greenwich Meridian' is the specific 0° longitude line running through the Royal Observatory, Greenwich. The term 'prime meridian' is the general concept, but it universally refers to the Greenwich Meridian in the modern context.
Theoretically, any line of longitude could be chosen as a prime meridian. Historically, different countries used their own (e.g., Paris, Washington). However, since 1884, the Greenwich Meridian has been the internationally accepted prime meridian for consistency in mapping, navigation, and time zones.
Greenwich Mean Time (GMT) is the mean solar time at the prime meridian. All other global time zones are defined as being a certain number of hours ahead of or behind GMT (e.g., GMT+1, GMT-5).
The meridian at 0° longitude, from which all other longitudes are measured.
Prime meridian is usually formal/technical in register.
Prime meridian: in British English it is pronounced /ˌpraɪm məˈrɪd.i.ən/, and in American English it is pronounced /ˌpraɪm məˈrɪd.i.ən/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “[No common idioms for this specific technical term]”
Learning
Memory Aids
Mnemonic
PRIME = First, Primary. MERIDIAN = Midday line. Remember it as the 'first midday line' from which we start counting the world's longitudes.
Conceptual Metaphor
The spine of world time; The starting line in the race of longitudes; The world's longitudinal home base.
Practice
Quiz
What is the primary function of the prime meridian?