ENGLISH
REFERENCE

pseudo

adj. · n.
US //ˈsudoʊ// UK //sˈuːdəʊ// pseu·do
  1. 1 fake or false (adj.)
    B2 Upper Intermediate

    not real or honest, even if it looks like it is.

    spurious or sham; appearing to be one thing while being another in reality.

    Example

    He gave a pseudo apology that didn't sound sincere at all.

    Example

    The building was decorated in a pseudo-Gothic style that many architectural critics found gaudy and historically inaccurate.
  2. 2 a pretentious person (n.)
    C1 Advanced Informal

    someone who tries to act more intelligent or important than they really are.

    an intellectually pretentious person or a poseur who lacks genuine depth.

    Example

    Don't listen to him; he's just a pseudo who wants to sound smart.

    Example

    The gallery was filled with pseudos who spent more time discussing the price of the art than the techniques used to create it.
  3. 3 online nickname (n.)
    B2 Upper Intermediate Informal Computing

    a fake name used on the internet to stay anonymous.

    a pseudonym or false name adopted for online anonymity.

    Example

    I never use my real name on forums; I always use a pseudo.

    Example

    To protect her privacy while investigating the data leak, she operated under a pseudo that could not be traced back to her employer.
  4. 4 medication (n.)
    C2 Proficiency Informal Technical Medicine

    a short name for a common medicine used to clear a blocked nose.

    a common clipping for pseudoephedrine, a sympathomimetic drug used as a nasal decongestant.

    Example

    The pharmacist said I needed to show my ID to buy any medicine containing pseudo.

    Example

    Due to its potential use in the illicit manufacture of stimulants, the sale of pseudo is strictly regulated in many jurisdictions.
    • decongestant
Origin

From Middle English, derived from prefix pseudo-, itself derived from Ancient Greek ψευδής (pseudḗs, “false, lying”).

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

Last updated June 20, 2026