adv ·Uncommon ·Advanced level

Definitions

Adverb

1. 1
   In an accidental manner; by chance, unexpectedly.

   "He discovered penicillin largely accidentally."

2. 2
   Unintentionally.

   "He accidentally exposed the bacteria to mold spores."

Adverb

1. 1
   without advance planning wordnet
2. 2
   without intention; in an unintentional manner wordnet
3. 3
   of a minor or subordinate nature wordnet

Synonyms

All synonyms

casuallyfortuitouslyaccidentalby accidentby chanceby chance

Antonyms

All antonyms

advertentlyadvisedlyby choiceby design

Example

More examples

"Willie accidentally let off his father's shotgun and made a hole in the wall."

Etymology

From accidental + -ly.

Related phrases

accidentally on purpose

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.