Noun
grunt work (uncountable)
(idiomatic) Work (especially that which is heavy, repetitive or mindless) that is considered undesirable and therefore delegated to underlings.
He plans to hire somebody to do the grunt work of digging the trenches for the pipes.
Writing is total grunt work. A lot of people think it's all about sitting and waiting for the muse. I don't buy that. It's a job. There are days when I really want to write, days when I don't. Every day I sit down and write. Jodi Picoult
It's just impossible to ignore the activists in your party. These are the people who stuff the envelopes, and walk the precincts, and make the telephone calls, and do all the so-called grunt work that brings about a successful campaign. Pat Robertson