\Re*["e]n"ter\ (r?*?n"t?r), v. t.
1. To enter again.

2. (Engraving) To cut deeper, as engraved lines on a plate of
   metal, when the engraving has not been deep enough, or the
   plate has become worn in printing.

\Re*["e]n"ter\, v. i.
To enter anew or again.

{Re["e]ntering angle}, an angle of a polygon pointing inward,
   as a, in the cut.

{Re["e]ntering polygon}, a polygon having one or more
   re["e]ntering angles.