monophthongal

enUK

mon·oph·thong

M0397000 (mŏn′əf-thông′, -thŏng′)n.1. A single vowel articulated without change in quality throughout the course of a syllable, as the vowel of English bed.2. Two written vowels representing a single sound, as oa in boat.
[Late Greek monophthongos : Greek mono-, mono- + Greek phthongos, sound.]
mon′oph·thon′gal (-thông′gəl, -thŏng′-) adj.