English Reference
noun

afterthought

n.
US /ˈæftɝˌθɑt/ UK /ˈɑːftəθˌɔːt/ af·ter·thought UK spelling afterthoughted, afterthoughts

  1. 01 B2 Upper Intermediate

    something added to a plan or a conversation later because it was forgotten at the start.

    an item, idea, or detail added to a plan or statement subsequently, often implying it was not part of the original design.

    Simple

    The small balcony felt like an afterthought because it was too tiny to use.

    In context

    The final chapter of the report seemed like a mere afterthought, lacking the rigorous analysis present in the earlier sections.

    Usage

    Often used with the preposition 'as' or 'an', as in 'added as an afterthought'.

    Teacher's tip

    This word often carries a slightly negative nuance, suggesting that the thing was not important enough to be planned properly.

    prioritypremeditation
  2. 02 C1 Advanced Formal

    a thought that comes to you after you have already done or said something.

    a reflection or secondary thought occurring after an action has been completed.

    Simple

    It was only as an afterthought that I realized I had forgotten my keys.

    In context

    Upon further reflection and as a quiet afterthought, he admitted that his initial reaction had been somewhat hasty.

    reconsiderationreview

You don’t get a telephoto camera with Samsung’s wider foldable, but this sensor increasingly feels like an afterthought for the Ultra.

Ars Technica· 14 Aug 2026

Etymology tree Proto-Indo-European *h₂epó Proto-Indo-European *-teros Proto-Indo-European *h₂ep(o)teros Proto-Germanic *after Old English æfter Middle English after English after ▲ Old English æfter Old English æfter- Middle English after- English after- Proto-Indo-European *teng-der. Proto-Germanic *þankijaną Proto-Germanic *þanhtaz Proto-West Germanic *þą̄ht Old English þōht Middle English thought English thought English afterthought From after- + thought, probably modelled on forethought. Compare also the verb afterthink.

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

This entry
Level B2 · Upper Intermediate
Frequency Occasional
Updated