retroflex

adjective

ret·​ro·​flex ˈre-trə-ˌfleks 

1

: turned or bent abruptly backward

2

: articulated with the tongue tip turned up or curled back just under the hard palate

retroflex vowel

Word History

Etymology

New Latin retroflexus, from Latin retro- + flexus, past participle of flectere to bend

First Known Use

1776, in the meaning defined at sense 1