re·en·trant also re-en·trant 
(rē-ĕntrənt)
(rē-ĕntrənt)adj.
1. Reentering; pointing inward.
2. Music Of or relating to strings that, when plucked in order, make a discontinuously rising and falling sequence of pitches: a lute with reentrant tuning.
n.
A reentrant angle or part.