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.
Plod, v. t. To walk on slowly or heavily.
The ploughman homeward plods his weary way. Gray.