- of or relating to a period of 15 years or the 15th occurrence of a series, as an anniversary.
- a 15th anniversary.
Origin of quindecennial
< Latin quīndec(im) fifteen + -ennial (as in decennial)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- occurring once every 15 years or over a period of 15 years
- a 15th anniversary
C20: from Latin quindecim fifteen + annus year, on the model of biennial