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alter

v. · n.
US //ˈɔɫtɝ// UK //ˈɒltɐ// al·ter
  1. 1 to change something (v.)
    B2 Upper Intermediate Academic

    to change something slightly, often to make it better or more suitable.

    to make a structural or formal change to something without replacing it entirely.

    Example

    We had to alter our travel plans because the flight was cancelled.

    Example

    The researchers were forced to alter their hypothesis after the initial data revealed a significant correlation they had not previously considered.

    Usage

    Often used with a direct object; can also be used without an object to mean 'to become different'.

    Pitfall
    He went to the church to pray at the alter.
    He went to the church to pray at the altar.

    Do not confuse 'alter' (to change) with 'altar' (a table used in religious ceremonies).

  2. 2 to tailor clothes (v.)
    B2 Upper Intermediate

    to change a piece of clothing so that it fits you better.

    to adjust the dimensions of a garment for a better fit.

    Example

    The trousers were too long, so I took them to a tailor to have them altered.

    Example

    She decided to alter the vintage dress herself, narrowing the waist and shortening the hem to create a more contemporary silhouette.

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  1. 3 to neuter an animal (v.)
    C1 Advanced American English Medicine

    to perform a medical operation on an animal so it cannot have babies.

    to castrate, neuter, or spay a domestic animal.

    Example

    The animal shelter requires all owners to alter their pets before adoption.

    Example

    Veterinarians generally recommend that owners alter their dogs at a young age to prevent unwanted litters and certain health complications.

  2. 4 an alternate personality (n.)
    C2 Proficiency Technical Psychology

    one of several different personalities that a person might have in some mental health conditions.

    a distinct personality state or identity within an individual, typically associated with dissociative identity disorder.

    Example

    The patient described how an alter would sometimes take control during stressful moments.

    Example

    Clinical observation focused on the transition between the primary identity and a protective alter during the therapeutic session.

    Usage

    Used as a countable noun in clinical psychology.

Etymology 1

From Old French alterer (French altérer), from Medieval Latin alterāre (“to make other”), from Latin alter (“the other”), from al- (seen in alius (“other”), alienus (“of another”), etc.; see alias, alien, etc.) + compar. suffix -ter.

Etymology 2

Probably from alter ego.

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