挖

The soldiers are dredging (up) the mud from the riverbed.

A million tons of rich ore was excavated from one pocket.

dredge/scoop up sludge from a pond

dig/sink a well

dig an air-raid shelter/a trench

dig/scoop a hole

mine coal

excavate a cellar

dig/excavate/sink a tunnel

pick one's nose

dig for treasure/wild edible plants

dig out some information (on/about); extract some information (from sb)

probe into the source/root of the problem

steal sb's best people; steal/drain the brains (of another institution); poach the brains (of another institution); skim off the best minds/people (of an institution)

exploit/tap the potential

dig/ferret out the hidden enemy