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."

(at something) Go to plug away (at something).

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.