1A region where the characteristics of one adjacent section or division give way to those of another, sometimes exhibiting features of both.
2Specifically. Botany. The region in a plant axis where the structures of the root meet those of the shoot or stem.
The thin layer of the sun's atmosphere between the chromosphere and the corona, produced by heat flowing from the latter into the former.
4The region between the passband and stopband in the frequency response of a filter.
In a semiconductor device: the junction between an N-type and P-type semiconductor.
transition region/tranˈzɪʃn ˌriːdʒ(ə)n/ /trɑːnˈzɪʃn ˌriːdʒ(ə)n/ /tranˈsɪʃn ˌriːdʒ(ə)n/
Early 19th century. From transition + region.