Sarcastically this adjective means the icing on top of the hypothetical shit cake(a really terrible no good very bad day)
A super obnoxious adjective usually emphasized in a high pitched tone to rub in how extremely wonderful and amazing your day was
Thanks for asking mom. My Monday was just FANFUCKINGTASTIC.
A no hussle having, lame ass, wanna be plug.
Drew Gross's DO-BOI skills are nowhere near as on point as Tony Pierce's.
Tony Pierce should write a book on "THE ART OF DO-BOING".