digdeep (third-person singular simple presentdigs deep, present participledigging deep, simple past and past participledug deep)
(idiomatic) To make a lot of effort with all one's resources.
If you want to join the marines, there's no room for laziness. You really have to dig deep.
2011 February 1, Phil McNulty, “Arsenal 2-1 Everton”, in BBC:
Arsene Wenger's side showed little of the style and fluidity that is their hallmark but this was about digging deep and getting the job done, qualities they demonstrated and that will serve them well as the season reaches its climax.