Definition of plods:
(v) :
(intransitive) To walk or move slowly and heavily or laboriously (+ on, through, over).
(v) :
(intransitive) To toil; to drudge; especially, to study laboriously and patiently.
(n) :
A slow or labored walk or other motion or activity.
(v) :
(transitive) To trudge over or through.
(n) :
(UK, mildly derogatory, uncountable, usually with "the") the police, police officers
(n) :
(UK, mildly derogatory, countable) a police officer, especially a low-ranking one.