Source : Webster's Revised Unabridged Dictionary (1913)

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®

ploddingly
     adv : in a plodding manner; "this writer ploddingly accumulates
           detail after detail"