Meanings
- not comparablerareOccurring every seventeen years; pertaining to or designating a seventeen-year interval.
The septendecennial emergence of Magicicada septendecim represents one of the most remarkable synchronized reproductive cycles in the animal kingdom, with entire broods surfacing after precisely seventeen years underground.
2025, Henry Feinberg, Entomological Patterns and Lexical PrecisionSynonyms: heptadecennial
Synonyms & antonyms
adjectiveOccurring every seventeen years; pertaining to or designating a seventeen-year interval.
Origin
From Latin septendec(im) (“seventeen”) + -ennial, after biennial, septennial, etc. By surface analysis, septen- + decennial.
Full word history & related roots →Cite this entry
septendecennial. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/septendecennial
“septendecennial.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/septendecennial. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “septendecennial,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/septendecennial.
Source: septendecennial on Wiktionary, CC BY-SA 4.0.