ENGLISH
REFERENCE

fossil

n. · adj.
US //ˈfɑsəɫ// UK //fˈɒsəl// fos·sil
  1. 1 ancient remains (n.)
    B2 Upper Intermediate Science

    the remains of a plant or animal that have turned into stone over millions of years.

    the mineralised remains or traces of an organism from a past geological age.

    Example

    The children found a small fossil of a shell while walking along the beach.

    Example

    The discovery of a well-preserved dinosaur fossil in the desert provided researchers with new insights into the species' social behaviour.
  2. 2 outdated person (n.)
    C1 Advanced Informal Humorous

    an unkind way to describe a person who is very old or has very old-fashioned ideas.

    a derogatory figurative term for an elderly person or someone perceived as being hopelessly behind the times.

    Example

    My boss is such a fossil; he still wants us to send everything by fax.

    Example

    The younger engineers viewed the department head as a fossil who refused to adopt modern software solutions.
  3. 3 fossil word (n.)
    C2 Proficiency Technical Linguistics

    a word that is only used in one specific phrase and is not used anywhere else in modern English.

    a word preserved in a specific idiom or frozen phrase while having otherwise fallen out of general use.

    Example

    The word 'fro' in the phrase 'to and fro' is a fossil because we don't use it alone anymore.

    Example

    Linguists often study fossil words like 'kith' to understand the historical development of English collocations.

    Usage

    Usually appears in the compound 'fossil word'.
    • archaic word
  4. 4 preserved or ancient (adj.)
    B2 Upper Intermediate Science

    relating to or being a fossil.

    pertaining to, of the nature of, or converted into a fossil.

    Example

    The museum has a large collection of fossil bones from the Jurassic period.

    Example

    The environmental impact report focused on the preservation of fossil tracks discovered during the initial excavation of the site.
Origin

From French fossile, from Latin fossilis (“something which has been dug up”), from fodio (“to dig up”).

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

Related words

Last updated June 20, 2026