noun

• (countable, uncountable, chiefly British, Australia and Canada) A long, tedious walk or march.
• (countable, uncountable, chiefly British, Australia and Canada, by extension) A hard, persistent effort, session of work, or period.
  "It is as if Mr. Faulks had bled his own prose white, draining it of emotion in order to capture the endless enervating slog of war."
• (countable) A book or other media that is difficult to get through due to dullness, density, or lack of narrative momentum.
• (countable, cricket) An aggressive shot played with little skill.

verb

• (intransitive) To walk slowly or doggedly, encountering resistance.
  "The leading engine was one of the Class Y6 2-8-8-2 compound articulateds, [...] The stack noise of one of these great brutes slogging up a grade was quite unforgettable."
• (intransitive, by extension) To work slowly and deliberately at a tedious task.