Arduous trek (4)

I believe the answer is:

slog

(Other definitions for slog that I've seen before include "Work doggedly" , "Hit out without style" , "Wild cricket hit" , "Long tedious task" , "big hit" .)

I've seen this clue in The Wall Street Journal.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.