Rude, mean, exhibiting poor manners. This
definition is old
school. It was often used by older folks correcting children who are, well, being ugly. This definition hasn't anything to do with one's physical appearance. However it can be used more generally, like talking about a person who cussed you out, talking ugly to you. Another example is when you have to tell something the ugly truth, like saying " I don't mean to be ugly but..."
Then there's of the definition of not being considered aesthetically appealing, repulsive
Redd Foxx came up with all kinds of jokes on Sanford and Son, his character Fred Sanford firing off incessant remarks about Esther, being ugly. It has become a staple, especially in African
American humour in
TV and movies, for example Madea's brother Joe talking about a battery acid chemical peal to
scrub all that ugly off her face.
Don't hit your
sister,
brother, etc. That's ugly.
I don't mean to be ugly, but you shouldn't be ugly towards
people like that
God don't like ugly (in the sense of not treating others right)
Redd Foxx: Vengeance is mine, and ugly is yours.