a. particularly inept activity or behavior
b. supremely clumsy or uncoordinated
"The smell of dog poop led me to believe that she was rather deft defying"
Pun or mondegreen for death-defying.
Consider that "death-defying" is an adjective for a stunt or action that should kill you, but you escape (defy) death.
Deft: skilled in movement, especially of the hands.
Defy: oppose, resist, challenge, or refuse to submit.
You can see why "deft defying" doesn't make much sense. Taken literally, "deft defying" could be used to describe someone that is skilled at opposition or physical resistance, as in "defying deftly".
If hyphenated to become an adjective, "deft-defying" could be used to describe someone either unskilled on purpose, or should be skilled and is not.
"That PETA arsonist did some deft defying in the hospital he burned down. Must have been difficult pushing through all those sick people to get out before it was too late, but that's less people benefiting from animal testing I guess."
"I tried that new masseuse... oh man, her massage was deft-defying. She needs to practice; I was sore for a week."
"Did you catch my deft-defying gaming skills to let my little brother beat me in Mortal Kombat? He doesn't know it, but I like letting him think he won fair and square."
"Did you just call that jump deft defying? Don't you mean death-defying? And it was only off the garage -- you wouldn't die from landing twelve feet, dude. You're an ass."