rank on (someone or something)
slang To criticize or complain about someone or something in a petty and naggingly critical manner. You know, the way you rank on the boss all the time is getting pretty old. So many people waste their breaths ranking on the government but won't vote or take any action to improve things.
rank on someone
Sl. to attack someone verbally; to gossip about someone. Please stop ranking on my family! Tom keeps ranking on Jennifer, and she is really mad about it.