Definition of septennial in English:
 septennial
adjective sɛpˈtɛnɪəlsɛpˈtɛniəl
1Recurring every seven years.
 Example sentencesExamples
-  The breaks would be largely funded by workers saving part of their salary so they can enjoy the septennial sabbatical.
 
- 1.1 Lasting for or relating to a period of seven years.
 the Septennial Act of 1716 extended the life of Parliament to seven years
 Example sentencesExamples
-  He said people generally say that Karvy is a septennial plant that is it flowers every seven years.
 
 
Origin
  
Mid 17th century: from late Latin septennis (from Latin septem 'seven' + annus 'year') + -al.
   Definition of septennial in US English:
 septennial
adjectivesɛpˈtɛniəlsepˈtenēəl
1Recurring every seven years.
 Example sentencesExamples
-  The breaks would be largely funded by workers saving part of their salary so they can enjoy the septennial sabbatical.
 
- 1.1 Lasting for or relating to a period of seven years.
 the Septennial Act of 1716 extended the life of Parliament to seven years
 Example sentencesExamples
-  He said people generally say that Karvy is a septennial plant that is it flowers every seven years.
 
 
Origin
  
Mid 17th century: from late Latin septennis (from Latin septem ‘seven’ + annus ‘year’) + -al.