ENGLISH
REFERENCE

solar

adj. · n.
US //ˈsoʊɫɝ// UK //sˈəʊlɐ// so·lar
  1. 1 related to the sun (adj.)
    B1 Intermediate Science

    connected with the sun or coming from the sun.

    pertaining to or proceeding from the sun. Usually non-gradable.

    Example

    The solar system includes the sun and all the planets that move around it.

    Example

    Scientists observed a massive solar flare that released a burst of radiation toward the Earth's atmosphere.

    Usage

    Usually placed before the noun it modifies.
    • heliocentric
  2. 2 using sun power (adj.)
    B1 Intermediate

    using the energy from the sun to make electricity or heat.

    utilising or powered by solar radiation.

    Example

    Many houses now have solar panels on their roofs to save money on energy.

    Example

    The government is investing heavily in solar technology to reduce the nation's reliance on fossil fuels.
  3. 3 solar energy (n.)
    B2 Upper Intermediate Informal

    energy or power that comes from the sun.

    a shortened form of 'solar energy' or 'solar power'. Uncountable in this sense.

    Example

    We decided to switch to solar to help the environment.

    Example

    The transition to solar has been faster than expected due to the falling cost of battery storage.
  4. 4 medieval room (n.)
    C2 Proficiency Archaic Technical

    a private upper room in a medieval house.

    a private room or upper chamber in a medieval English house, often used by the family for privacy away from the main hall.

    Example

    The lord and lady of the castle slept in the solar above the great hall.

    Example

    Architectural historians noted that the solar provided a rare degree of domestic privacy in an otherwise communal medieval structure.
Etymology 1

From Late Middle English solar, from Latin sōlāris, from sōl (“sun”), from Proto-Indo-European *sóh₂wl̥ (“sun”).

Etymology 2

From Middle English solar, soler; from a conflation of Old English soler, solere (“raised platform; loft, upper room, upper part of a house, soler”), from Latin sōlārium; and Old English solor, salor (“residence, dwelling; hall; palace”), from Proto-West Germanic salaʀ, from Proto-Germanic salaz, *salą (“house, room, hall”). More at sale.

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

Related words

Last updated June 19, 2026