ugly as sin

(as) ugly as sin

Extremely visually displeasing or unattractive. This old car is all beat up and ugly as sin, but it's still going strong after all these years. I'm sure I looked as ugly as sin by that point, with my makeup smeared all over the place and my hair a total mess.
See also: sin, ugly
Farlex Dictionary of Idioms.

*ugly as sin

Cliché extremely ugly. (*Also: as ~.) Why would anyone want to buy that dress? It's as ugly as sin! Harold is ugly as sin, but his personality is very charming.
See also: sin, ugly
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

ugly as sin

Physically or morally hideous, as in I can't think why she likes that dog; it's ugly as sin. This simile, first recorded in 1801, replaced the earlier ugly as the devil.
See also: sin, ugly
The American Heritage® Dictionary of Idioms by Christine Ammer.

ugly as sin

If someone or something is as ugly as sin, they are very ugly. Even his kids were ugly as sin.
See also: sin, ugly
Collins COBUILD Idioms Dictionary, 3rd ed.

(as) miserable/ugly as ˈsin

(spoken) used to emphasize that somebody is very unhappy or ugly: He arrived at the party looking as miserable as sin. Some babies are as ugly as sin at that age.
See also: miserable, sin, ugly
Farlex Partner Idioms Dictionary

ugly as sin

verb
See as ugly as sin
See also: sin, ugly
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions

ugly as sin

Hideous, either physically or spiritually. This simile appears to have replaced the earlier ugly as the devil, mentioned by Daniel Defoe in his History of the Devil (1726). The first appearance in print was in Maria Edgeworth’s Popular Tales of 1804: “Why, she is ugly as sin!”
See also: sin, ugly
The Dictionary of Clichés by Christine Ammer
See also:
  • (as) ugly as sin
  • as ugly as sin
  • be (as) ugly as sin
  • (as) ugly as a toad
  • toad
  • ugly as a toad
  • pug-ugly
  • plug-ugly
  • fugly
  • fell out of the ugly tree and hit every branch on the way down
References in periodicals archive
It was the size and weight of a brick, ugly as sin and stopped working after a week.
CAN'T AFFORD OMEGA EITHER
The magazine described the cheap-to-run G-Wiz, which ended production in 2012, as "slow, not very safe and ugly as sin".
G-Wiz that's worst motor on the roads
After declaring in a blog post that GOPer Marilinda Garcia (with misspellings corrected), is "one of the most attractive women on the political scene anywhere, not so attractive as to be intimidating, but truly attractive," he went on to rant about the looks of Dem incumbent Annie Kuster, who he called "ugly as sin" (and for an added touch, added that he hoped he hadn't "offended sin").
If looks could kill
Of course, they'd have to go and watch another game because my lads are as ugly as sin."
You don't have to be mad to be a football manager.. but it helps
on the coal When she's bevied she's really a shocker She got a few bob when she left her last job Made redundant when she was a Docker She got 22 grand cash in her hand But even with that lump sum She does nothing but cry Cos hard as they try The doctors just can't fix her Hump I say, "Look so yer fat, well never mind "You're the one girl, I'll never ditch "With yer black toothy grin, yer ugly as sin "But let's face it, yer bloody well rich!" by Bobby Clinton, L5
Your Poem
An American radio vet who believes she's as ugly as sin gets a call from an English photographer with a troublesome dog.
FILMS OF THE WEEK
Ugly as Sin Why they changed our churches from sacred places to meeting spaces and how we can change them back again EDITED BY Michael S.
Ugly as Sin: why they changed our churches from sacred places to meeting spaces and how we can change them back again
"Some people think it's ugly as sin, other people think it's good looking on the line.
Found finds niche in Parry Sound. (Parry Sound)
I am positive there is no living Southern feminist worth a hoot who didn't spend a good chunk of her adolescence acting ugly as sin. It does get in your blood.
Kate Daniels acts ugly