quindecennial

adj — 2 senses

adj

Etymology From Latin quindecennialis, from quindecennium (“15-year period”) + -alis (“-al: forming adjs”). Equivalent to quindec- + -ennial.

Lasting fifteen years.

Happening once in fifteen years.

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.