reënter

CIDE DICTIONARY

reënter, v. t. 

•  To enter again.  [1913 Webster]
•  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.  [1913 Webster]

reënter, v. i. 

 To enter anew or again.  [1913 Webster]

Reëntering angle, an angle of a polygon pointing inward, as a, in the cut. -- Reëntering polygon, a polygon having one or more reëntering angles.