Vice-host
From Podpedia
Vice-host is a synonym of co-host, coined by Brady in "H.I. No. 86: Banana Republic" to refer to his position on Hello Internet.[1] Grey thought that the term vice-host was not the same as co-host, since vice-host implies that one host is more important than the other. He said that because Hello Internet was created by both of them equally, the term vice-host didn't make sense.