Someone said that which is the ugliest word in the English language (I don’t remember who said that; it was a well-known person, perhaps GBS ?).
Question 1. Do you agree ?
Question 2. How can we do without it, say, in a scientific paper ?
I don’t find the word “which” to be ugly.
I think the ugliest word in the English language is “packrat.” To me, this word sounds like someone clearing his throat and then spitting.
I’m a huge enemy of “moist”, myself.
“cunt.”
No not you, I’m just responding to your question. 
I think this is going to boil down to humble opinions, but I nominate ointment. Ther is something about ointment that gives me the willies.
I’m sure this is more IMHO stuff.
Anyway gangrene would be my vote.
Off from a Google search for “ugliest word” comes;
vulgarity, ergative, scrotum, blog, pulchritude, and usufruct.
I believe the author of that sentiment was actually Gordon W. Allport. Take a look at this essay (warning PDF file) entitled “Epistle to Thesis Writers.”
Allport offers guidance on that question as well
Writer H. Alan Smith said that the worst words in the English language are “Uh oh.” As when the mechanic lifts the hood when you are on a trip in N. Dakota and says, “Uh oh.” Or when the doctor looks at your chart and says, “Uh oh.”
I think Ugly is pretty ugly.
Are we talking about the way the word looks, sounds, or what it refers to?
Bastard. Most folks that are considered bastards are usually ugly too.
“Mucus”
If it had to be 2 words, then it would be “mucus membrane”.
This one is looking for opinions, not a factual answer to a finite question.
So, off to IMHO.
samclem GQ moderator
Leotard.
Though “ointment” does come close.
“Which” isn’t even in the ballpark. Heck, it isn’t even in the parking lot outside of the ballpark.
Stench
OH MAN! And “ointment”!!
“I’d like some moist ointment.”
GAAAAH!
Repugnant.
Vulva. This word is just nasty. I nominate “agenda” for a word that seems pretty innocuous but on repeated listenings sounds pretty vulgar.
Goiter.
That’s just nasty.
I’ll nominate ointment’s little used thesaurus neighbor unguent. Especially when Gaer “We split the car” Grimsrud says it in Fargo.
Doesn’t sound like anything I want rubbed into my body…ointment is not nearly as bad sounding to my ears.