shag + -tastic. Popularized by the Austin Powers movies.
shagtastic (comparative more shagtastic, superlative most shagtastic)
- (UK, slang) brilliant, with implications of sexual intercourse.
- 2008, Mike Parker, Neighbours from Hell (page 28)
- Hinting at sexual extravagance might have caused outrage and disgust in the mid 1800s, but in the shagtastic twenty-first century, it's a certificate of honour.