Word Study
trigraph
CIDE DICTIONARY
trigraph, n. [Pref. tri- + -graph.].
Three letters united in pronunciation so as to have but one sound, or to form but one syllable, as -ieu in adieu; a triphthong. [1913 Webster]
OXFORD DICTIONARY
trigraph, n. (also trigram)
1 a group of three letters representing one sound.
2 a figure of three lines.
1 a group of three letters representing one sound.
2 a figure of three lines.
ROGET THESAURUS
trigraph
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.For further exploring for "trigraph" in Webster Dictionary Online