ENGLISH
REFERENCE

lunar

adj. · n.
US //ˈɫunɝ// UK //lˈuːnɐ// lu·nar
  1. 1 relating to the moon (adj.)
    B2 Upper Intermediate Science

    related to the moon or its appearance.

    pertaining to the Earth's moon, its physical characteristics, or its orbital cycles.

    Example

    The lunar surface is covered in craters and grey dust.

    Example

    The lunar cycle significantly influences tidal patterns across the globe, a phenomenon that has been studied by navigators for centuries.
  2. 2 moon travel/exploration (adj.)
    B2 Upper Intermediate Science

    related to travelling to the moon or studying it.

    pertaining to space travel between Earth and the moon, or the scientific exploration of the moon.

    Example

    The astronauts collected many lunar rocks to bring back to Earth.

    Example

    The success of the lunar landing in 1969 marked a pivotal moment in human history and technological achievement.

  3. 3 crescent-shaped (adj.)
    C1 Advanced Formal

    shaped like a crescent moon.

    having a shape that resembles a crescent moon; lunate.

    Example

    The artist decorated the bowl with small lunar patterns.

    Example

    The architect incorporated several lunar curves into the building's facade to soften its otherwise sharp, modern edges.
  4. 4 wrist bone (n.)
    C2 Proficiency Technical Medicine

    a small bone in your wrist that is shaped like a half-moon.

    the middle bone of the proximal series of the carpus in the human wrist.

    Example

    The doctor checked the lunar bone for any signs of a fracture.

    Example

    A fracture of the lunar bone often requires specialised imaging to ensure the joint remains stable during the healing process.
    • lunate bone
  5. 5 navigation measurement (n.)
    C2 Proficiency Archaic Technical Science

    a measurement of the distance between the moon and a star used to find a ship's position.

    an observation of the angular distance between the moon and another celestial body, used to determine longitude at sea.

    Example

    The sailor took a lunar to check the ship's position.

    Example

    Before the invention of the marine chronometer, taking a lunar was the primary method for determining longitude during long ocean voyages.

    Usage

    Usually used in the context of historical maritime navigation.

Origin

From Middle English lunar (“shaped like the crescent moon”), from Latin lūnāris (“of or pertaining to the moon, lunar”) (possibly through Middle French lunaire (modern French lunaire (“lunar”)), from lūna (“the Moon; crescent shape”) (ultimately from Proto-Indo-European *lewk- (“bright; to shine”)) + -is (suffix forming adjectives).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Related words

Last updated June 20, 2026