decennial
UK[dɪˈsɛnɪəl]US[dɪˈsɛnɪəl]
adj
Happening every ten years or lasting for ten years.
n
A tenth anniversary or its celebration.
Morpheme Breakdown
dec
enn
ial
dec
ten
enn
year
ial
adjective suffix
Etymology
The word 'decennial' is a modern English formation built directly from classical Latin components. Its core is the numeral 'decem' (ten) combined with 'annus' (year), a pairing that logically denotes a ten-year period. The Latin suffix '-alis' was added to form an adjective, a pattern seen in many temporal terms like 'centennial' and 'millennial'. The word's journey into English reflects a scholarly borrowing during the Renaissance, preserving the Latin roots' precise mathematical and temporal relationship to describe events or durations spanning a decade.
Analysis
Structure: dec (ten) + enn (year) + ial (adjective suffix)
dec: From Latin decem, meaning "ten". A numerical root.
enn: From Latin annus, meaning "year". The spelling is altered to 'enn' in compounds.
ial: A Latin-derived adjectival suffix meaning "relating to or characterized by".
Examples
The government conducts a decennial census to gather population data.
The university celebrated its decennial with a series of public lectures.
They are planning for the decennial review of the environmental policy.