reentrant

The story

1. Proto-Italic*wre-
2. Latinre-
3. Old Frenchre-
4. Middle Englishre-
5. Englishre-
6. Englishentrant
7. English todayreentrant

From re- + entrant.

First known use, by meaning

• from 18th c. Designating a structure at an angle pointing inward towards the centre of the fortification; opposed to salient.
• from 18th c. Pertaining to an angle pointing inwards, or to a line forming part of such an angle.
• from 20th c. Pertaining to a type of angular valley cutting deep into the side of a hill or mountain.
• from 20th c. Pertaining to a type of cardiac arrhythmia in which an impulse re-excites an area that has already been stimulated.
• from 20th c. Designating a way of tuning the strings of certain stringed instruments, such that they follow a pattern of rising and falling intervals, rather than having successively higher pitches.
• from 20th c. That may be executed more than once at a time either by different threads, or because of recursion.