monophthongize

[mon-uh f-thawng-ahyz, -gahyz, -thong-]Phonetics
verb (used without object), mon·oph·thong·ized, mon·oph·thong·iz·ing.
  1. to become a monophthong.
Also especially British, mon·oph·thong·ise.

Origin of monophthongize

First recorded in 1875–80; monophthong + -ize
Related formsmon·oph·thong·i·za·tion, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018