quindecennial

quin·de·cen·ni·al

 (kwĭn′dĭ-sĕn′ē-əl)
adj.
1. Occurring once every 15 years.
2. Lasting 15 years.
n.
A 15th anniversary.

[From Latin quīndecim, fifteen; see penkwe in Indo-European roots + Latin -ennium (from annus, year; see at- in Indo-European roots).]

quindecennial

(ˌkwɪndɪˈsɛnɪəl)
adj
occurring once every 15 years or over a period of 15 years
n
a 15th anniversary
[C20: from Latin quindecim fifteen + annus year, on the model of biennial]
References in periodicals archive ?
Bergman, Chairman of the Board and Chief Executive Officer of Henry Schein, accepted the honor on behalf of the Company at the Quindecennial Healthcare Diversity Awards, held June 25 at the New York Academy of Medicine in New York, N.
Key-in quinquennial for a fifth, decennial for a tenth, and quindecennial for a fifteenth.