ಪ್ರತಿ 20 ವರ್ಷಗಳಿಗೊಮ್ಮೆ ಸಂಭವಿಸುತ್ತದೆ,

Adjective:

ಇಪ್ಪತ್ತು ವರ್ಷಗಳ ಬಾಳಿಕೆ,

vicennial's Usage Examples:

summarized developments to the propaganda model on the occasion of the vicennial anniversary of first publication of Manufacturing Consent.

For comparison, the June 1963 value is comparable to a vicennial flood event, and is thus considered not that exceptional.

elections of December 1937, upon the end of Greater Romania"s liberal vicennial.

Sabathia was one of the most dominant pitchers in the vicennial (twenty year) period of 2000 to 2020; posting more wins, games started.

recognition of a quarter century spent as an active duty soldier, and almost vicennial record of his service with the ROTC.