I'm not sure this is 100% accurate, but this is the word I've heard as I grew up, went to school there, and came back to teach at Washburn Rural.
Back in the day, Washburn High School was affiliated with Washburn University, which was named for a fella by the name of Ichabod Washburn (hence, the mascot of the university, a goofy guy in a top hat and coattails that is supposedly the image of Ichabod Washburn himself). Washburn High School was the Junior Ichabods - we still have that goofy little mascot with the top hat and coattails.
A little while after that, Washburn school district consolidated with the Auburn school district and became Auburn-Washburn. Somewhere in there, the high school changed its location from 19th and Hope in Topeka to 61st and Wanamaker (back then, it was pretty far in the boondocks, hence, the name "Washburn Rural"). The affiliation with the university ended and they changed the name from the Jr. Ichabods to the Jr. Blues, even though the guy looks the same.
Now we have an image (this one is pretty cool looking) of the Jr. Blue painted full-size on our wrestling mat... if you've seen it at our tournament or at one of our duals, it's pretty sweet looking!