To slug out text means to rapidly produce solid lines of lead type, known as slugs, using a machine like a Linotype or Intertype. The operator types at a keyboard to assemble brass matrices, which the machine then fills with molten metal to cast a single, solid line. It implies a fast, continuous rhythm of mechanical typesetting to meet a deadline.
Heard on the job
I need you to slug out the late sports scores right now so we can lock up this form.