ENGLISH
REFERENCE

monitor

n. · v.
US //ˈmɑnətɝ// UK //mˈɒnɪtɐ// mon·i·tor
  1. 1 computer screen (n.)
    A2 Elementary Computing

    the screen that shows pictures and words from a computer.

    an electronic visual display for computers, typically consisting of a screen and its housing.

    Example

    I bought a second monitor so I could see my emails and my work at the same time.

    Example

    The graphic designer invested in a high-resolution monitor to ensure that the colour reproduction was accurate for the print campaign.
  2. 2 a person who supervises (n.)
    B2 Upper Intermediate

    someone whose job is to watch a situation to make sure it is fair or safe.

    an individual appointed to supervise, observe, or verify the conduct of a specific process or group.

    Example

    The exam monitor walked around the room to make sure no one was talking.

    Example

    International monitors were deployed to the region to oversee the election and ensure the voting process remained transparent.
Show 4 more sensesShow fewer
  1. 3 medical or technical device (n.)
    B1 Intermediate Medicine

    a piece of equipment that checks and shows information, like your heart rate.

    an instrument or device used for observing, checking, or keeping a continuous record of a process or quantity.

    Example

    The nurse checked the heart monitor to see if the patient was sleeping well.

    Example

    The technician calibrated the radiation monitor before entering the laboratory to ensure the safety of the research team.
  2. 4 to watch and check (v.)
    B1 Intermediate

    to watch something carefully over a period of time to see how it changes.

    to observe and check the progress or quality of something over a period of time; to keep under systematic review.

    Example

    The doctors will monitor her condition closely for the next twenty-four hours.

    Example

    The environmental agency continues to monitor air quality levels in the city to determine the impact of the new traffic regulations.
  3. 5 a large lizard (n.)
    C1 Advanced Technical Science

    a type of large lizard found in Africa, Asia, and Australia.

    any of various large tropical lizards of the genus Varanus, known for their powerful builds and predatory nature.

    Example

    We saw a large monitor sunning itself on a rock near the river.

    Example

    The Komodo dragon is the largest extant species of monitor, reaching lengths of up to three metres in the wild.
    • monitor lizard
    • varanid
  4. 6 armoured warship (n.)
    C2 Proficiency Archaic Technical

    a small, slow warship with very large guns used near the coast.

    a relatively small, slow-moving armoured warship designed for coastal bombardment rather than naval combat.

    Example

    The museum has a model of a nineteenth-century monitor used in the war.

    Example

    The shallow draft of the monitor allowed it to navigate river estuaries that were inaccessible to the larger ships of the line.
Origin

From Latin monitor (“warner”), from perfect passive participle monitus (“warning”), from verb monere (“to warn, admonish, remind”). Warship sense is from USS Monitor, the first ship of this type.

© 2026 English Reference