资料来源 : pyDict

三字一音,三重音字

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Trigraph \Tri"graph\, 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.