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Naming Nine Things

Date: 01/15/2003 at 09:41:22
From: Connie P. (Middle School Math teacher)
Subject: Naming nine things (like 3 is triplet)

What is the correct name for nine things collectively?  I can only 
fine the answer up to 7, septuplet, which has been highly publicized 
with the McCoy babies. I am guessing nonet because non as in nonagon 
represents a nine-sided figure.

Date: 01/15/2003 at 10:16:48
From: Doctor Peterson
Subject: Re: Naming nine things (like 3 is triplet)

Hi, Connie.

You've got the right basic idea, though our FAQ lists enneagon rather 
than nonagon, because "non-" is the Latin prefix for 9 while "ennea-" 
is the Greek prefix, which fits better with the Greek "-gon".

My dictionary (American Heritage) lists "octuple," "nonuple," and 
"decuple," so the natural thing is to add a "t" to each to make the 
form you want for a set of babies:


I notice my dictionary doesn't even list "septuplet," probably 
because there hadn't been any when it was published; but "sextuplet" 
is listed as formed by combining "sextuple" with the ending of 
"triplet," supporting this assumption. Even lists only up to 
sextuplet, and it doesn't include octuple or nonuple but does have 

In math, the corresponding term would just be "9-tuple"; why use 
words when numbers will do? In music, you would use "sextet,"
"septet," "octet," "nonet"; these are all listed in

If you have any further questions, feel free to write back.

- Doctor Peterson, The Math Forum 
Associated Topics:
Elementary Definitions
Elementary Number Sense/About Numbers
Middle School Definitions
Middle School Number Sense/About Numbers

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