Diss
-I'm sorry if I dissed you that day dude, I was just really busy.
-If you diss someone and you don't know how they will react, you can really get into a fight.
-She dissed him by saying he had no money and his shoes were old.
Meaning: To speak disrespectfully to or criticize someone.
Origin: An abbreviation of the word 'disrespect'
******
Other examples:
1. Mom I'm sorry if I dissed you this morning by hanging up the phone, I was just very busy this morning; I had to record a show.
2. She dissed him because he showed up wearing shabby clothes.