deca- [DEK uh], dec-, deka-, dek-Deca- or deka-  symbol da is a decimal unit prefix in the metric systemdenoting a factor ropt ten. The prefix was a part of the original metric system in It is not in very common usage, although the deca pascal is occasionally used by audiologists. The deca root word examples newton is also encountered occasionally, deca root word examples because proviron body hair is an SI approximation of the kilogram-force. Its use is more common in Central Europe. In German, Polish, Czech, Slovak and Hungarian, deka or deko is common and used as a word on its own, always meaning decagram.
Deca- - Wikipedia
In this page, I discuss a curious set of unusual words: What do you call a group of eleven musicians? An athletic competition with six events? An event that recurs every twenty years? It can be very difficult to figure out what sort of prefix to use, and there are plenty of exceptions to the rules. Because many of these words aren't found in dictionaries particularly as the relevant numbers get larger , having some general principles can help.
Thus, where other word lists of the Phrontistery are simply listed in "word: In general, these words are made by combining a prefix derived from Latin or Greek number words and a suffix indicating the type or category of the thing being counted. If you know a lot of word etymologies, you can usually figure out whether a word takes a Latin or Greek numerical prefix if you can tell whether the suffix you want to use is Latin or Greek in origin.
However, if you can't work out the etymology, it's probably best to just look at the lists below, which indicate which prefixes are used with which suffixes.
Besides, there are exceptions to this general rule. In this first table, I've listed the Latin words for 1 through 12 along with the appropriate prefix that is derived from it. For each of the above categories, check the appropriate column and find the word list.
In cases where the word couldn't be found in regular dictionaries, I've extrapolated from the other words and used appropriate prefixes and endings to construct the correct form.
In such hypothetical cases, the word is marked with an asterisk and put it in italics. So far, so good. Since I'm not being hardline about "proper" forms, I'm including all the forms normally used, even when they don't strictly follow the rules. Up to 12, the Latin prefixes hold up pretty well; most of the forms exist; only "sexilateral", of all the hypotheticals, is less than nine.
My theory is that it sounds too lewd to have been adopted as the term for something with six sides. The situation with the Greek terms is a little more complex than with the Latin, but not excessively so. Latin prefixes are used for some words for polygons, although the Greek prefix is to be preferred.
Of course, this is partly because there's no such thing as a two-faced polyhedron, and not much point in describing a single athletic event as a "monathlon" So far, we've stuck to the numbers 1 through We have pretty solid sequences of words, although the words relating to 9 and 11 are, to be fair, extremely rare. But moving to the teens, decades, and , the words become much more sparse.
Still, given the right adjectives and a little creativity, we can construct many hypothetical words that should be understandable. Table 3 lists the higher Latin numbers and prefixes. I'll stick to listing the numerical bases and adjectives of relation, and let you figure out the rest on your own, on the pattern described above. Most of the other terms aren't found in dictionaries how often do you need to describe something that recurs every 60 years?
Now, things get complicated. For the teens, things are made complex by the fact that instead of "duodeviginti" literally 'two-from-twenty' and "undeviginti" 'one-from-twenty' for 18 and 19, the prefixes for them are 'decennoct' ten-eight and 'decennov' ten-nine. I suspect, again, that prudishness has led to "hexadecimal" getting the nod over "sexadecimal".
Actually, other than "hexadecimal", all these words for 13 through 19 are extremely rare to non-existent, so it might be best to just forget about them. Moving on to the decades, most of these are also quite rare. However, many nouns exist, derived from the appropriate adjectives of relation, which identify a person of a particular age; "octogenary" becomes "octogenarian" - someone in their eighties.
For the higher Greek numbers, there's almost no evidence in English for the use of these words, but mathematicians sometimes need words for polygons and solid figures, so here are the appropriate prefixes and words for , and The ancient Greek teens all contain the conjunction kai "and", but except for 13 and 14, the prefixes used in English normally omit it.
All of the words in Table 4 are very rare if they are found at all , except for icosahedron. Note that in modern Greek, the numerals for the teens are different than the ancient forms, reversing triskaideka to dekatreis , tettares kai deka to dekatettares , and so on. Now that I've outlined some of the basic features and rules to allow you to construct your own numerical words on the basis of those outlined here, I've compiled a triskaidecad of unusual facts and trivia relating to this very interesting topic.
I hope you have found this site to be useful. If you have any corrections, additions, or comments, please contact me. Please note that I am not able to respond to all requests. Please consult a major dictionary before e-mailing your query.
Links to this page may be made without permission. Let's turn to the Greek prefixes mono, di, tri And now, Table 2 shows us the Greek numeral words and prefixes in conjunction with the appropriate suffixes for the above categories.