miserable/ugly as sin

(as) miserable as sin

Extremely unhappy, depressed, or wretched. Everyone just stood around looking miserable as sin during the ceremony. I felt as miserable as sin because of the breakup, but I was going to be best man at my brother's wedding, so I had to pick myself up and dust myself off.
See also: miserable, sin

(as) ugly as sin

Extremely visually displeasing or unattractive. I wouldn't buy that painting, it's as ugly as sin. I'm sure I looked ugly as sin, with my makeup smeared all over and my hair a total mess.
See also: sin, ugly

*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

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

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

(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

ugly as sin

verb
See also: sin, ugly

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