what's the word for ...

General Questions
#1

We have annual for every year, biennial for every two years. What is the word for every ten years?

#2

how’s this for a guess?

Decannual??
Deciannual??
Decaannual??

#3

decennial

“If you had manifested fatigue upon noticing that you had been an ass, that would have been logical, that would have been rational; whereas it seems to me that to manifest surprise was to be again an ass.”
Mark Twain
Personal Recollections of Joan of Arc

#4

Similarly, duodecennial for 12 year and sesquicentennial for 150 year celebrations.

And sesquipedalian, literally ‘foot-and-a-half-long’ for many syllabled words or speech.

Finally, Susquehanna is a river flowing from central New York to Chesapeake Bay.

“If you had manifested fatigue upon noticing that you had been an ass, that would have been logical, that would have been rational; whereas it seems to me that to manifest surprise was to be again an ass.”
Mark Twain
Personal Recollections of Joan of Arc

#5

Susquehanna was also the name of a hat manufacturing company in an old Abbot and Costello routine.

I always remember the important stuff.

Wally Haiku

#6

Positively my last post here – see the current thread about secondary, tertiary, etc.

http://www.straightdope.com/ubb/Forum3/HTML/002900.html

With the -ennial ending most of the words are the same: vicennial = 20 years, etc.

“If you had manifested fatigue upon noticing that you had been an ass, that would have been logical, that would have been rational; whereas it seems to me that to manifest surprise was to be again an ass.”
Mark Twain
Personal Recollections of Joan of Arc

#7

The U.S. Government takes a decennial census.

You can look up Supreme Court decisions (the old-fashioned way) in West’s Decennial Digests.