English Reference
adverb

accidentally

adv.
US /ˌæksəˈdɛnəɫi/ UK /ˌæksɪdˈɛntəli/ ac·ci·den·tal·ly

  1. 01 B1 Intermediate

    by mistake or without planning it.

    unintentionally or by mistake; describes an action performed without deliberate purpose.

    Simple

    I accidentally deleted the email while I was trying to move it to a folder.

    In context

    The witness accidentally revealed the location of the safe house during the cross-examination, much to the frustration of the legal team.

    Usage

    Usually placed before the main verb or at the end of a clause.

    Pitfall
    I accidently broke the glass. I accidentally broke the glass.

    A common spelling mistake is to forget the 'al' in the middle. Remember: accident + al + ly.

  2. 02 B2 Upper Intermediate

    happening by luck or chance rather than being planned.

    occurring by chance or unexpected coincidence rather than design.

    Simple

    We met accidentally at the train station after not seeing each other for years.

    In context

    The researchers accidentally discovered the new compound while they were investigating a completely unrelated chemical reaction.

    fortuitouslyby chance
    calculatedly

Most fires are started by humans, whether deliberately or accidentally, but this summer's hot and dry weather has created ideal conditions for blazes.

BBC News· 14 Aug 2026

The concept centers on the idea of accidentally slipping out of normal reality and becoming trapped in this monotonous, labyrinthine environment with no clear exit.

ScienceDaily· 26 Jul 2026

From accidental + -ly.

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

This entry
Level B2 · Upper Intermediate
Frequency Common
Updated