A combination of 'slut' and 'fantastic'. Describes a person displaying copious amounts of said trait; in this case the individual would be fantastically slutty. User-created words such as this are often casually thrown out at the discretion of the speaker (ex. Fergalicious).
A humorous and perfectly cromulent portmanteau of "sarcastic" and "fantastical." That which is sartastical is fantastically sarcastic, or indicative of extravagantly fanciful sarcasm.
Person A: "Problematical is a perfectly cromulent word."
Person B: "It embiggens even the poorest writers among us."
Person C: "That's ironical, isn't it?"
Person D: "Actually, that's sartastical."