"Chamfered edges" refers to the technique of smoothing or beveling the corners or edges of an object to create a slight angled or sloping surface. Full definition
The Blade's body consists of an aluminum frame with chamfered edges with a rubberized black back with a diamond pattern. (techradar.com)
The phone is made from all metal as it uses a full metal unibody design, complete with chamfered edges on both the front and back, and a glass display that is slightly curved (very subtly) at the edges all the way around so the glass of the display kind of melts into the edges of the body. (androidheadlines.com)
My all - black model looks nice in a generic way, with subtle chamfered edges around the rims, though the design isn't inspired. (cnet.com)