< L decennis, lasting ten years < decem, ten + annus, year (see annual) + -ary
decennary in American English
(dɪˈsenəri)
Word forms: nounplural -ries
noun
1.
a decennium
adjective
2.
pertaining to a period of ten years; decennial
Word origin
[1815–25; ‹ L decenn(is) of ten years (dec(em) ten + -ennis, comb. form of annus a year) + -ary]This word is first recorded in the period 1815–25. Other words that entered Englishat around the same time include: aesthetic, coupon, treadmill, trolley, welterweight-ary is a suffix occurring originally in loanwords from Classical and Medieval Latin,on adjectives (elementary; honorary; stationary; tributary), personal nouns (actuary; notary; secretary), or nouns denoting objects, esp. receptacles or places (library; rosary; glossary). The suffix has the general sense “pertaining to, connected with” the referent namedby the base; it is productive in English, sometimes with the additional senses “contributingto,” “for the purpose of,” and usually forming adjectives. Other words that use theaffix -ary include: complimentary, inflationary, revolutionary, visionary