Definition of coincidental adjective from the Oxford Advanced American Dictionary

  

coincidental

 adjective
adjective
NAmE//koʊˌɪnsəˈdɛntl//
 
[not usually before noun]
 
jump to other results
happening by chance; not planned I suppose your presence here today is not entirely coincidental. It's purely coincidental that we both chose to name our daughters Emma.
coincidentally
 
jump to other results
NAmE//koʊˌɪnsəˈdɛntli//
 
, NAmE//koʊˌɪnsəˈdɛntəli//
 
adverb Coincidentally, they had both studied in Paris.
See the Oxford Advanced Learner's Dictionary entry: coincidental