Synonyms for Plodding (same or very similar meaning)
WordNet sense 1 ((of movement) slow and laborious):
leadenWordNet sense 2 (requiring great physical effort):
effortfulWordNet sense 3 (hard monotonous routine work):
drudgery, grind, donkeyworkWordNet sense 4 (the act of walking with a slow heavy gait):
plodFrom the ODE community, based on WordNetadd/edit