Original meaning is a thingamajig in US slang and it can be used to conceal the meaning from children, strangers etc. Usually tools. In the later 20th Century it came to mean an informal party with music.
Don dropped his spanner under the hood. Dang! Pass me my hootenanny.
A gathering of like-minded people with folk music sometimes incorporating dancing, with no less than four fat girls and hosted by your favorite local feed store.
Hey I heard Palo Cedro feed was having a hootenanny September 8th we should go down there is going to be no less than for fat girls and beer.
It's a NAME for a Gay Lesbian Chick who thinks she runs shit. And nobody even knows who she is, so that's why she's mad in the first place. Because he's really a she.
That's why you a "bald-headed hootenanny."
I hear that Neil Young will be playing at the fairgrounds hootenannie this week.