English Reference
adjective · noun

unforeseen

adj. · n.
US /ˌənfɔɹˈsin/ UK /ʌnfɔːsˈiːn/ un·fore·seen

  1. 01 B2 Upper Intermediate

    adj.describes a situation or event that you did not see coming or expect to happen.

    adj.not anticipated or predicted; occurring without prior warning or expectation.

    Simple

    The project was delayed due to unforeseen problems with the building's foundation.

    In context

    The company's sudden bankruptcy was precipitated by a series of unforeseen market shifts that rendered their primary product line obsolete overnight.

    Usage

    Usually placed before the noun it describes, such as 'unforeseen circumstances' or 'unforeseen consequences'.

    unexpectedunpredictedsudden
  2. 02 C1 Advanced FormalTechnical

    n.things that happen which were not planned or expected, often used when talking about extra costs.

    n.events, incidents, or costs that were not anticipated. Often functions as a collective noun in formal or technical contexts.

    Simple

    We should keep some extra money in the budget for the unforeseen.

    In context

    The contract includes a specific clause to account for the unforeseen, ensuring that neither party is unfairly penalised by external disruptions.

    Usage

    Typically preceded by the definite article 'the' to function as a collective noun.

She's not far away." While Hunt finally broke the 11-second barrier in the 100m for the first time this season, there have been unforeseen challenges as far as the 200m is concerned.

BBC News· 17 Aug 2026

From un- + foreseen.

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

This entry
Level B2 · Upper Intermediate
Frequency Occasional
Updated