Slang, Vulgar Produced in an incompetent or desultory manner, or of something lacking in quality or substance; of low rank; incompetent.
the only abortion she could get even in the city would be a half-ass job by some half-ass doctor who could mess her up for the rest of her life1969, The End of the Road by John Barth (page 155)
Slang, Vulgar To perform a task incompletely or carelessly.
Near-synonyms: phone in, shortchange, underdo
Now, we go out there and we half-ass it because we're scared, all we're left with is an excuse. We're always gonna wonder. But, we go out there and we give it absolutely everything… that's heroic.1999, W. Peter Iliff, Varsity Blues, spoken by Mox (James Van Der Beek):
1 more example
if you're working for me and I send you to do a job and you half-ass it, that reflects on me. In civilian life, we'd just fire you. Here I can't get rid of you.2002, Guardians of the Eagle by John D. Messer (page 102)