say it: ak-suh-DEN-tuh-lee
accidentally is an adverb meaning "without advance planning". It carries 3 recorded senses.
of a minor or subordinate nature
“these magnificent achievements were only incidentally influenced by Oriental models”
without intention; in an unintentional manner
“she hit him unintentionally”
Definitions, synonyms and semantic relations for accidentally come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.