accidentally meaning
EN
[ˌæksəˈdɛnt(ə)li] 
US - AdverbCOMmore accidentallySUPmost accidentallySUF-ly
- In an accidental manner; unexpectedly; by chance; casually; fortuitously.
- He discovered penicillin largely accidentally.
- Unintentionally.
- He accidentally exposed the bacteria to mold spores.
- In an accidental manner; unexpectedly; by chance; casually; fortuitously.
- More Examples
- Used in the Middle of Sentence
- I accidentally bumped into him, and he flipped me the bird.
- She accidentally rubbed up against the painted door and got green paint on her blouse.
- I accidentally saved my unwanted changes and overwrote the version of the document I wanted to keep.
- Used in the Middle of Sentence
Definition of accidentally in English Dictionary
- Part-of-Speech Hierarchy
- Adverbs
- Act-related adverbs
- Manner adverbs
- Act-related adverbs
- Morphemes
- Suffixes
- Words by suffix
- Words suffixed with -ly
- Words suffixed with -ly
- Words by suffix
- Suffixes
- Adverbs
Source: Wiktionary
Grammatically, this word "accidentally" is an adverb, more specifically, an act-related adverb and a manner adverb. It's also a morpheme, more specifically, a suffixe.