An adjective with the loosest definition in the world. It can be good, bad, ugly, and everything in between. The word's origin is American English, combining the word 'fantastic' with the redneck nickname 'buck'. Hilarity ensues.
"Wow, I can't believe you just fucked that squirrel."
"Me neither... she was feisty."
"She?? That was a HE, dude."
"Damn. That sucks."
"No dude, thats bucktastic."