Tedious work (5)
'tedious work' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for grind that I've seen before include "drudgery" , "Pulverise" , "Crush into particles" , "Hard dull work" , "To prepare coffee beans" .)
(Other definitions for drudgery that I've seen before include "tedium" , "Tedious toil" , "Dull menial work" , "Grind" , "Menial hard work" .)