The metaphorical act of unwillingly being fucked in the ass, often times in the workplace by superiors or colleagues who dump work on you and then blame you for their mistakes. Often times, a standalone statement used to punctuate a sentence. Can also be used as a verb.
"My boss just volunteered me to do more work in that meeting. FINTA."
"Those people are entirely incompetent and I'll have to do their work to meet this deadline. FINTA"
"That c-nt totally FINTA'ed me today."
"Everyday, I show up to my office and feel like I'm being FINTA'ed off the bat."