"Fugly" is a vulgar slang adjective as far as I know, and I wonder how common it is, and how do people react when they hear that word. Native speakers are appreciated if they share their opinions.
"Fugly" is indeed both vulgar and slang. When I was growing up it in Chicago, it was understood as a combination word built of f***-ugly, where the first word is one of the proverbial words you can't say on the radio.
As a combination that was often used on the playground, it has less impact than the core four letter word. But Horatio's description of it sounds about right - a direct insult.
Fugly is used in Britain, amongst certain groups of disreputable youths, as it is American slang, it must get in to the youth culture dialects via the usual media route.
However, there are far more common slang words that are very similar and used instead.
- a contraction of butt-ugly, slightly better form than using fugly
(unless you have heard teen girls use it to bully someone, in which case any semblance of decency would fade beneath your jading eyes)
- generally meaning "repulsive", from the Scots word mingin with the meaning "stinking", note it is also used for events/things that are disgusting in addition to the descriptive use for people
NB. Often used in the form of an agent noun instead, minger (there is also munter, but I refuse to explain what munting means and strongly suggest no one looks it up if you want to retain your latest meal)
- meaning "disgusting" and "repulsive" now, converted from the still used, more standard meaning of "malodorous"
This word has a long etymology, originally from the Old English ranc, see Online Etymology's account (the adjectival form)
- should be self explanatory in this context
- meaning "unclean" or "disgusting"
I have seen mixed etymology on this, some say originating in London, others that it is from the French manqué (from manquer - "to lack, to miss out, to fail") and my personal view, the adjectival form of the archaic Scots word mank, meaning "maimed" - the Scots use manky far more than elsewhere in the past. It fits with the current use best, any body part that is maimed would certainly be referred to as manky.
Dictionary.com reports only that fugly means very ugly, extremely unattractive; it doesn't report if it is vulgar, or slang.
Searching for fugly in the Corpus of Contemporary American, I find that the frequency that word is used is 0.01 per million in fiction, and 0.02 per million in magazines; it is not used in other contexts. The word is only found in texts dated between 2005-2010 (with a frequency of 0.03).
I didn't find the word in the British National Corpus, but it doesn't contain data for texts after 1993.
Does what you are wearing make me think of you as more feminine or more elegant or more provocative or more intellectual or more street than I thought before? And please forgive my chauvinism, but do I fancy you more? A label in itself is no guarantee of desirability. A hot designer's clothes can be brilliant or flat-out fugly. I think women on the whole are more interested to know how they are being assessed by other women; maybe they feel the details are wasted on men. But as a man, when I see women in outlandish getups, I certainly have some kind of internal dialogue with myself that comes under the heading "What were you thinking?" —When Women Try too Hard, Christopher Brooks.