Answer: plodded

AnswerCrossword Clue
PLODDEDMarched through mud
PLODDEDMoved effortfully
PLODDEDTrudged.
PLODDEDTrudged
ploddedPLOD, to walk heavily
ploddedWalk doggedly and slowly with heavy steps
ploddedWork slowly and perseveringly at a dull task