A derisive and condescending term insultingly used by women when referring to a man that they are in a conversation with. The man's point is derided not because his reasoning is faulty or his evidence is unreliable; his point is derided simply on the basis of his gender.
"Thanks for showing me the screengrab that proves the video is fake. I was not sharing it because I believed the video; I was sharing it because I thought it was funny. You do not need to mansplain the facts of it to me. I don't care."