Green’s Dictionary of Slang

joanie n.

[? the character Joanie in the US sitcom Happy Days, set in late 1950s and early 1960s; note joan n.]

(US teen) an out-of-date, unfashionable young woman.

[US]Dly Record (Morristown, NJ) 28 Oct. 25/3: Telling you to wear something because they want you to show up looking like a joanie, you know?
‘Valley Girls’ on Paranoiafanzine 🌐 But, really, I mean, half of the whole Val image is our totally raspy way of speaking. So I, like, put this together so you won’t go around sounding like a total zod or something. Just, like, try and get it right, and don’t be a total joanie, okay?