To do something with little effort.
Not completely done.
Little or no effort is used in the job/activity.
"Why did you do a half ass job cleaning your room? There are dirty clothes under your bed."
1: "How did you get a 57% on that essay? It was easy."
2: "I did a half ass job writing it."
Something done poorly, a bad job, a rushed task the person could have done better at.
I told him to clean his room and he did a halfass job!
(adj). Something incomplete or downright lame, disappointing in its partial quality. Often a task given to a teenage student is done in a half-ass manner.
You are an hour late and telling me you couldn't get a cab? That's a half-ass excuse!
2)No done with quality
Frankilton half-ass did the work
The act of doing something without motivation or care as to the quality of the object at hand. To not give a shit.
Jon: "Damn we have a paper due tommorow?"
Chris: "Dude, don't fucking half-ass that shit."