First of all I have to note this word's origin came from Britain and commonly used in the subculture of its type. The Austin Powers films widely popularized the term.

I believe it's original meaning is : "Sexy in a psychedelic or colorful way." and I think that based off of studying the culture and context it was used in.

And so my friends, 'Keep the good times rollin!!!' Yah Baby Yah!!

P.S. The word Shag is related to sex and fuck, but I think it's much more eloquent and groovy baby.
I think you're shagadelic baby! You're switched on! You're smashing!

Oh no, baby. You're very shagadelic. I just didn't want to fall in love again, and I thought you'd never love me without my mojo. It's not you. You're fab, you're switched on, you're a bit of alright! YES!

Well, I can't believe Sir Steven Spielberg, the grooviest film maker in the history of cinema, is making a movie about my life. Very Shagadelic, baby, yeah.
by MAGNUMUS CONDOMUS December 26, 2015
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An orgasmic quality inherent in the object, event or person experienced.
That babe was shagadelic.
by Bungalow Bill January 30, 2002
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AUSTEN POWERS BABY! THIS IS THE BEST WORD IN HISTORY!
Anything good really. Idk someone: “Honey I got you some milk!” You when using this awesome word “OMG SHAGADELIC THANK YOU!”
by Anne Shirley. June 25, 2022
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The phrase coined by Austin Powers star Mike Myers as he 'compliments' his female assistants.
Austin: "Fancy a shag?"
Girl: "...what?"
Austin: "Oh, you're shagadelic baby, YEAH!"
by Crazy Axer July 16, 2009
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