The Wizards of Middle-Earth...

[Celegost]

I was reading the prologue of The Fellowship of the Ring when I found something in the Concerning Pipe-Weed section which made me think.....Are there other Wizards in Middle-Earth besides the Istari? Throughout The Lord of the Rings and the Hobbit, Tolkien writes about Wizards as if they are a whole other race of beings.
For example, in the aforementioned sentence: "And certainly it was from Bree that the art of smoking the genuine weed spread in the recent centuries among Dwarves and such other folk, Rangers, Wizards , or Wanderers as still passed to and fro through that ancient road-meeting." the use of Wizards suggests that more than one Wizard smoked pipe-weed. This is odd because the Hobbits could only have known of one Wizard who smoked pipe-weed (Gandalf), because even though Saruman did as well, he had it transported to Isengard secretly. Radagast might have visited Bree once or twice, but I thought he was more interested in Nature, as for the other two, they travelled into the east, far away from Bree.
There are lots more descriptions of Wizards as if there are a lot more of them besides the Istari, especially in the Hobbit (but I cant be bothered to look them up right now).