What is a synonym for ugly?

There are many synonyms for "ugly," depending on the context and nuance you want to convey. Here are some options, categorized by their level of intensity:

Mild:

* Unattractive

* Plain

* Homely

* Unsightly

* Unpleasant

* Unprepossessing

* Unappealing

Moderate:

* Hideous

* Repulsive

* Grotesque

* Disgusting

* Abhorrent

* Disagreeable

* Offensive

Strong:

* Monstrous

* Deformed

* Ghastly

* Horrific

* Appalling

* Repugnant

* Vile

Figurative/Metaphorical:

* Awful

* Dreadful

* Shocking

* Disturbing

* Grievous

* Heinous

* Atrocious

Informal:

* Yucky

* Gross

* Nasty

* Bleah

* Ugh

The best synonym will depend on the specific situation and the level of intensity you want to express.