ROGET THESAURUS
triphthong
Letter
N
letter, character, hieroglyphic, type, capitals, digraph, trigraph, ideogram, ideograph, majuscule, minuscule, majuscule, minuscule, alphabet, ABC, abecedary, christcross-row, consonant, vowel, diphthong,
triphthong, mute, liquid, labial, dental, guttural, syllable, monosyllable, dissyllable, polysyllable, affix, suffix, spelling, orthograph, phonography, phonetic spelling, anagrammatism, metagrammatism, cipher, monogram, anagram, doubleacrostic, literal, alphabetical, abecedarian, syllabic, majuscular, minuscular, uncial.