lacus solis

C2 (Extremely Rare / Technical)
UK/ˌleɪ.kəs ˈsəʊ.lɪs/US/ˌleɪ.kəs ˈsoʊ.lɪs/

Scientific, historical astronomy, poetic.

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Definition

Meaning

A large, dark basaltic plain on the surface of the Moon, historically mistaken for a lake.

A specific lunar mare (sea) located on the Moon's near side. In broader astronomical or poetic context, can refer to any sun-related lake or metaphorical place of solar origin.

Linguistics

Semantic Notes

"Lacus Solis" is a Latin term meaning "Lake of the Sun." It is not a modern standard IAU (International Astronomical Union) lunar feature name but appears in historical lunar cartography (e.g., by Giovanni Riccioli). It corresponds approximately to the Mare Nubium region.

Dialectal Variation

British vs American Usage

Differences

No significant differences in usage. Both use the Latin term identically in technical contexts.

Connotations

Evokes historical astronomy, classical scholarship, and poetic imagery.

Frequency

Virtually never used in everyday language. Equally rare in both UK and US specialized texts.

Vocabulary

Collocations

strong
historical maps oflocated nearthe region of Lacus Solis
medium
observeidentifyfeature called
weak
studyreference toknown as

Grammar

Valency Patterns

[Lacus Solis] + [verb: is located/ appears/ was charted] + [prepositional phrase]The [feature/ mare] + [known as/called] + [Lacus Solis]

Vocabulary

Synonyms

Strong

Lake of the Sun (direct translation)

Neutral

Mare Nubium (modern equivalent)lunar mare

Weak

dark lunar plainbasaltic flow region

Vocabulary

Antonyms

lunar highlandsterrae

Phrases

Idioms & Phrases

  • None in common usage.

Usage

Context Usage

Business

Not used.

Academic

Used in historical papers on astronomy or the history of science.

Everyday

Not used.

Technical

Used in specialized contexts discussing pre-20th century lunar nomenclature.

Examples

By Part of Speech

verb

British English

  • The feature was once labelled 'Lacus Solis' on lunar maps.
  • Early astronomers misidentified and named it Lacus Solis.

American English

  • Riccioli charted and designated the area Lacus Solis.
  • You can locate Lacus Solis on that 17th-century engraving.

adverb

British English

  • Not applicable (no adverbial use).

American English

  • Not applicable (no adverbial use).

adjective

British English

  • The Lacus Solis region appears darker through the telescope.
  • He studied the Lacus Solis coordinates.

American English

  • A Lacus Solis reference appears in the old text.
  • The map shows the Lacus Solis feature clearly.

Examples

By CEFR Level

B2
  • Lacus Solis is an old name for a dark area on the Moon.
  • Some old maps of the Moon show Lacus Solis.
C1
  • The historical lunar feature Lacus Solis, or 'Lake of the Sun,' corresponds to part of the Mare Nubium.
  • In his 1651 work, Riccioli included Lacus Solis among his nomenclature for lunar 'lakes.'

Learning

Memory Aids

Mnemonic

Think: 'SOL' is the Sun, and a LAKE (lacus) on the moon named after it. 'The Sun's Lake on the Moon.'

Conceptual Metaphor

THE MOON'S SURFACE IS A MAP WITH TERRESTRIAL FEATURES (seas, lakes).

Watch out

Common Pitfalls

Translation Traps (for Russian speakers)

  • Do not translate as "солнечное озеро" in a modern lunar context; it is a proper name. Use the Latin term or explain as "историческое название лунного моря."
  • Avoid confusing with Russian "море" (more) for lunar mare; Lacus Solis is a specific historical 'lake'.

Common Mistakes

  • Using it as a current astronomical term. / Pronouncing 'Solis' with a hard 's' (should be /s/). / Treating it as an English compound noun (e.g., 'the Lacus Solis').

Practice

Quiz

Fill in the gap
On Giovanni Riccioli's 17th-century map, the dark patch now known as Mare Nubium was labelled .
Multiple Choice

What is 'Lacus Solis' primarily associated with?

FAQ

Frequently Asked Questions

No. It is a historical name for a dark, dry plain on the Moon mistaken for a lake by early astronomers.

Only in a historical context. The modern standardized name for the region is Mare Nubium (Sea of Clouds).

It is Latin for 'Lake of the Sun.'

It is an example of the historical practice of naming lunar features after earthly bodies of water, contributing to the history of science.