(UN-2 6 a.)

1

  Now spec. in phonetics: cf. ROUND v. 1 c. Also Unrounding vbl. sb.

2

1611.  Cotgr., Desrondir, to vnround, vnbow, vncompasse.

3

1648.  Hexham, II. Ontronden, to vnround, or take away the roundnesse of any thing.

4

1874.  H. Sweet, in Trans. Philol. Soc., 471. Rounded front vowels are often unrounded. Ibid., 475. Rounding of back [vowels]; unrounding of front. Ibid. (1877), Handbk. Phonetics, 25. This vowel … is best obtained by unrounding (u).

5