plod

1. VERB

If someone plods, they walk slowly and heavily.

• Crowds of French and British families plodded around in yellow plastic macs.
  

2. VERB

If you say that someone plods on or plods along with a job, you mean that the job is taking a long time.

• He is plodding on with negotiations.     
• Aircraft production continued to plod along at an agonizingly slow pace.

... Cobuild

v.intr.

1. To move or walk heavily or laboriously; trudge: "donkeys that plodded wearily in a circle round a gin" D.H. Lawrence.

2. To work or act perseveringly or monotonously; drudge: plodding through a mountain of paperwork.

v.tr.

To trudge along or over.

n.

1. The act of moving or walking heavily and slowly.

2. The sound made by a heavy step.

... Am-Heritage