Entry: diphthong (n.)
In context: "...she's pronounced beautiful like the earlier interested in four syllables, splitting the diphthong, betraying her class and origin with the heartbreaking openness Joelle's always viewed as either terribly stupid or terribly brave..."
Definition: A union of two vowels pronounced in one syllable; the combination of a sonantal with a consonantal vowel.
SNOOT score: 2
Source: Oxford English Dictionary