No, don't use use mongoloid to refer to Down's syndrome in any form of English, it's offensive.
The Downs Syndrome Association advise the media of What To Say / Not Say, including:
Don't Say: Mongol
Do Say: person/baby/child with Down's syndrome
Down's Syndrome Scotland recently issued a statement, this is much more relevant to informal English, and I'll quote it in full:
Statement regarding Ricky Gervais' use of "Mong" on Twitter
(24 October 2011) Last week Ricky Gervais, a well known comedian as
well as writer and actor in The Office, tweeted his followers using
“Good monging” and “Goodnight twongols”. Since these tweets and others
last week appeared, the media and Twitter followers have been voicing
their various viewpoints.
Ricky Gervais defends his use of the word, saying that the word has
changed its meaning.He tweeted:“Just to clarify for uptight people
stuck in the past. The word Mong means Down’s syndrome about as much
as the word Gay means happy. i.e. I never use the word Mong to mean
anything to do with Down’s syndrome.”
However, the comedian continued to post photos similar to this one.
The tweet above reads: “Goodnight tweetmonglers…This face is for you
guys….” These photos do little to prove that the meaning has changed
from a derogatory term used to refer to people with Down’s syndrome
who have some form of learning disability.
Where did “mong” come from?
The word “mong” derives from the word “mongol” and “mongoloid”. Dr.
John Langdon Down, who discovered Down’s syndrome in the 1860s, used
“mongolism” and “mongoloid” to describe the syndrome as he stated that
there were similar physical characteristics of people with Down’s
syndrome to people from Mongolia and Mongoloid race (those of Asian
ethnicity). This phrase was used until the 1960s, when scientists
petitioned to use “Down’s syndrome” instead of “Mongolism” or
“Mongoloid” as they were embarrassing terms for Chinese and Japanese
scientists and academics to use this word to refer to the syndrome.
Mongolia delegates from the World Health Organisation later requested
that the use of “mongolism” and “mongol” be dropped from WHO
Why is “mong” such an issue?
Today, the word “mong” is used quite frequently. However, have you
ever heard it used in a positive way? Have you used it to mean
“idiot”, “slow” or “stupid”? These words have been used throughout
history and today to refer to people with learning disabilities and
people with Down’s syndrome. Has the word really changed?
We have seen words like the “N word”, which referred to black slaves
in America change its meaning as some black people have taken back the
word and refer to their black friends as “nigga”. However, this word
is generally not used by white people as there is a respect and
understanding that the origins of the word represent oppression to
People with learning disabilities cannot reclaim the word “mong”.
People with learning disabilities are often left out of society. Due
to disproportionate cuts to their services, it's harder to secure jobs
and college places leaving people with learning disabilities stuck at
We know many people with Down’s syndrome face abuse on the street
every day including having the word “mong” shouted at them. When Ricky
Gervais or others with similar prominence use this word, people hear
it and think it’s alright to use this word how they see fit. Words hit
hard and punch you whether you’re up or down.
Not only is the word offensive to people with Down’s syndrome but it
is also offensive to Mongolians. If you were a Mongol, how would you
like to hear your nationality used as a word that meant “slow”,
“stupid” or “idiot”? In an age where people are seeing the
consequences bullying has on its victims, why would you promote a
negative word with negative pictures? This word is not only harmful to
people with Down’s syndrome but to Mongolians.
We encourage Ricky Gervais to speak to his local Down’s syndrome
organisation or phone us on 0131 313 4225 for more information. We are
happy to put him in contact with people with Down’s syndrome who can
explain what the word “mong” means to them. While you may not have
known that “mong” refers to Down’s syndrome, will you stop using it
now that you know? We hope to erase ignorance over the potency of this
word. By educating others on the harm this word does, we hope you and
others choose not to use it in the future. By doing so, you are
supporting a group in society that is often disregarded.
Read more about disablist language from Richard Herring.