the St Valentine's Day Massacre

Từ điển Oxford Advanced Learner 8th

the St Valentine’s Day Massacre [the St Valentines Day Massacre] BrE NAmE
the murder of seven US criminals in ↑Chicago on 14 February 1929. The men killed were members of ‘Bugs’ Moran’s ‘North Side gang’ and were shot by a group of Al Capone's men dressed as police officers. The murders shocked Americans and caused the Chicago police to increase their efforts against Capone. The incident has been shown in many films.