Can also be a "spurious boondoggle" when you have angry sex with her and then intentionally leave her unsatisfied.
"Man, I banged my ex-girlfriend last night and I'm still so pissed at her I spuriously boondoggled her."
2.- A hopeless Case
3.- Some sort of deformed toy made from parts of other different toys
"You're such a Boondoggle, all you like to do is drink urine while staring at the dead corpse of your grandma"
"Is that a Boondoggle you've got there, It's pretty badass, it must have costed a fortune"