peg away at

peg away (at something)

To continue trying or working diligently (at something). I'm really not very good at math, but I've got to keep pegging away at it if I want to get into an engineering program. A: "Where's John?" B: "Oh, he's out in the garden pegging away."
See also: away, peg
Farlex Dictionary of Idioms.

peg away at

Also, plug away at. Work steadily, persist, as in She pegged away at the tax return until she'd finished, or If we keep plugging away at it, the painting will soon be done. These idioms allude to the persistence required to fasten something by driving pegs or seal something by driving a plug. Peg away dates from the early 1800s plug away from the mid-1900s.
See also: away, peg
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • peg away
  • peg away (at something)
  • plug away
  • plug away (at something)
  • slug
  • slug away (at something)
  • hard at
  • hard at (something)
  • hard at it
  • nose to the grindstone
References in classic literature
"Heaven grant that they may be of a kind sufficiently noxious for the doctor to let me peg away at them!"
Five Weeks in a Balloon
Why should a grandson and grandfather peg away at each other with mutual wiolence when all might be bliss and concord.
The Old Curiosity Shop
I should be able to look after Ada's interests and my own interests (the same thing!); and I should peg away at Blackstone and all those fellows with the most tremendous ardour."
Bleak House