What is modified, as a vowel, by contraction of the lip opening, making the opening more or less round in shape; rounded; labialized; labial. See Guide to Pronunciation, § 11 called?

round — (Phonetics) Modified, as a vowel, by contraction of the lip opening, making the opening more or less round in shape; rounded; labialized; labial. See Guide to Pronunciation, § 11. (Webster's 1913.)

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