Emily Dickinson Lexicon

JOB, n. [of unknown origin, but perhaps allied to chop, primarily to strike or drive.]

1. A piece of work; any thing to be done, whether of more or less importance. The carpenter or mason undertakes to build a house by the job. The erection of Westminster bridge was a heavy job; and it was a great job to erect Central wharf, in Boston. The mechanic has many small jobs on hand.
2. A lucrative business; an undertaking with a view to profit. No cheek is known to blush nor heart to throb, / Save when they lose a question or a job. – Pope.
3. A sudden stab with a pointed instrument. [This seems to be nearly the original sense.] To do the job for one, to kill him.