bigamy
noun /ˈbɪɡəmi/
  /ˈbɪɡəmi/
 [uncountable]- the crime of marrying somebody when you are still legally married to somebody else compare monogamy, polygamyTopics Crime and punishmentc2, Life stagesc2Word OriginMiddle English: from Old French bigamie, from bigame ‘bigamous’, from late Latin bigamus, from bi- ‘twice’ + Greek -gamos ‘married’.