Definition: strike heavily, especially with the fist or a bat
Usage: He slugged me so hard that I passed out
Main entry: tramp, trudge, plod, pad, slog, footslog
Definition: walk heavily and firmly, as when weary, or through mud
Usage: Mules plodded in a circle around a grindstone
Main entry: plug away, peg away, keep one's nose to the grindstone, keep one's shoulder to the wheel, slog
Definition: work doggedly or persistently
Usage: She keeps plugging away at her dissertation