Definition of whereupon conjunction from the Oxford Advanced American Dictionary

 

whereupon

 conjunction
conjunction
NAmE//ˌwɛrəˈpɑn//
 
, NAmE//ˌwɛrəˈpɔn//
 
, NAmE//ˈwɛrəˌpɑn//
 
, NAmE//ˈwɛrəˌpɔn//
 
(formal)
 
jump to other results
and then; as a result of this He told her she was a liar, whereupon she walked out.
See the Oxford Advanced Learner's Dictionary entry: whereupon