The central plain chinese generally called the northern nomads (beyond the great wall of China) living in Mongolia, Manchuria etc as "Hu 胡" people. The "Hu 胡" is a generic term to refer to northern nomads such as XiongNu, Xianbei, Wuhuan, Uighur, Jie, Qiang, Tujue (Turks), Khitan, Jurchen etc. I read that the term "hu 胡" is of despising/derogatory nature that also mean 'uncivilized and barbaric' used by the han-chinese.

I'm just wondering about the origin of this term "hu 胡".

In literal sense, "hu 胡" means "beard" in chinese. Is it because alot of these northern nomads did not shave and grew beard in an untidy ungroomed (i.e. 'uncivilized' way), and that's why the chinese called them "Hu" (beard people)?

How did the chinese came to call the northern nomads "hu"?

It might have been shaped from the name Hun (Qun/Khun).

Note that the term Hù 胡 was also used for the Soghdians.

Is it from the this word Hun (Qun/Khun).>>>>>Hù 胡

Hun- means "MAN , PEOPLE" in Mongolian language

I don't think it meant beard in Traditional Chinese (simplification of 鬍 conflated it with 胡).
In 說文, the character胡 meant "牛顄垂也 從肉古聲", which is another part of body (for oxen/cows, not humans).
According to Starostin the old pronunciation of the character is (Classic Old Chinese) ghā with English meaning "dewlap"

There's another similar coincidence (sound similarity between the terms for 'barbarian' and 'beard'):
http://en.wikipedia.org/wiki/Barbarian
In Latin "barbarinus" looks similar to "barba" but then 'an alternative etymology of "barbarian" from the Latin barba, meaning beard is spurious.'

Hun sounds quite different from "ghā".. though somebody can say that some similar sound changes might also have happened in Mongolia.

It's Hú.

The earliest Chinese terms for northern nomads are Di (狄) and Hu (胡). Indeed, as grasy already said, the Shuowen Jiezi, the earliest Chinese dictionary from the Han era, explains that Hu (胡) comes from “meat” (rou, 肉) and is specifically the “wattle” or fleshy flap of the ox or cow. To trace the likely derivation in terms of the radicals in the character is perhaps the easy part: 古 + 肉 （which lies behind 月）＝ 胡. Presumably the 古 or “old” here refers to the wrinkled appearance of this fleshy protuberance. But why they chose to refer to these people in reference to the “cow’s wattle” is harder to ascertain. It could simply be a reference to their nomadic way of life and the importance of oxen therein or it could be some (refracted or distorted) interpretation of that people’s totemic beliefs. Basically I think we need to accept the humbling conclusion that no one can really know for sure at this point.

While some scholars apparently prefer taking the more usual meaning of the yue radical 月 (in Hu, 胡) as referring to the “moon”, thereby suggesting that the northern tribes were thought by their southern neighbors to have observed a lunar calendar, such a conjecture is not so likely in my view in that the so-called Hu were unlikely to have been the only ones to have followed the lunar calendar and hence regarded as especially deserving of such an appellation.

I think all this simply highlights the difficulty of getting behind such an ancient label using nothing more than philological tools. It can lead you in all kinds of weird directions depending on your scholarly fancy and there is little by way of controls to check the validity or merit of particular interpretations.

胡 = 古 + 肉 = 十 + 口 + 肉

Literally, it could project an image of "10 mouths sharing a piece of meat" ...

a nomadic practice?

從肉古聲 means that the meaning follows 肉 (flesh) and the sound follows 古.
Presumably 古 only represents the sound, no any relevance to its meaning. I don't think it's related in any way to "ancient". Just like, how can you find the relevance of "ancient" to 固 "firm/solid" and 苦 "bitter"?

It would be a contradiction to the meaning "dewlap" of the 胡. Similarity of 肉 to 月 is because of simplification that happened in LiShu 隸書.

So are you conjecturing that calling them 胡 is a coincidence (just because there's a character that looks like "十口肉")?

in contrary to the notion of "coincidence" ...

How you perceive a native american?
What kind of impressions that will come to your mind when someone ask you about the red indian?

For me, it is a picture of a party of people dancing around a fire (camp fire?) ... plus a "prey" on top of the fire ...
and most probably a big piece of burned meat (肉) will be passed around among these happy folks (十口)

If you don't think it's coincidence, then why would it be read the same as the 胡 of meaning "dewlap"?