Source : Webster's Revised Unabridged Dictionary (1913)

Plod \Plod\, v. i. [imp. & p. p. {Plodded}; p. pr. & vb. n.
   {Plodding}.] [Gf. Gael. plod a clod, a pool; also, to strike
   or pelt with a clod or clods.]
   1. To travel slowly but steadily; to trudge. --Shak.

   2. To toil; to drudge; especially, to study laboriously and
      patiently. ``Plodding schoolmen.'' --Drayton.

Plodding \Plod"ding\, a.
   Progressing in a slow, toilsome manner; characterized by
   laborious diligence; as, a plodding peddler; a plodding
   student; a man of plodding habits. --{Plod"ding*ly}, adv.

Source : WordNet®

plodding
     adj : (of movement) slow and laborious; "leaden steps" [syn: {leaden}]

plodding
     n 1: hard monotonous routine work [syn: {drudgery}, {grind}, {donkeywork}]
     2: the act of walking with a slow heavy gait

plod
     v : walk heavily and firmly, as when weary, or through mud;
         "Mules plodded in a circle around a grindstone" [syn: {slog},
          {footslog}, {trudge}, {pad}, {tramp}]
     [also: {plodding}, {plodded}]

plodding
     See {plod}