trigraph

n. group of three successive letters that make one sound

A trigraph (from the Greek words tria = three and grapho = write) is a group of three symbols, most commonly letters.Trigraphs are used in several fields, and for several purposes. Among them areIn computing:A C trigraph, a character representation in the C family of programming languages.As octal or decimal representation of byte values.Mnemonics for machine language instructions.There are text matching and data compression algorithms which act directly on trigraphs.In language:As language codes in ISO 639.A Trigraph (orthography), a sound representation in orthography.As abbreviations.In cryptography:As substitution group in a substitution cipher.As combinations in the Ling Qi Jing.
See more at Wikipedia.org...

(n.)
Three letters united in pronunciation so as to have but one sound, or to form but one syllable, as -ieu in adieu; a triphthong.
  

trigraph
danh từ nhóm ba chữ cái làm thành một âm tiết nhóm ba chữ cái kế tiếp nhau
(C) 2007 www.TừĐiểnTiếngViệt.net

TRIGRAFO