To bore through an existing hole, generally to correct its shape, or to enlarge.
If you want to keep using that rifle, you'll have to rebore the barrel.
The cylinders of your engine are so worn the rings don't seal any more; you have to have it rebored to stop it from burning oil.
1 more example
Every major bridge, and many of the smaller ones, have been rebuilt, tunnels have been rebored, and long sections of track realigned.1950 April, “Notes and News: The Athens-Salonika Railway”, in Railway Magazine, page 279:
However, any increase in capacity is useful and, if an engine is worn and needs a rebore, it's worth considering boring to a near maximum size rather than simply having it bored to the next oversize.2005, Daniel Stapleton, How to Plan and Build a Fast Road Car, page 14: