esagramma

A hexagraph (from the , héx, "six" and γράφω, gráphō, "write") is a sequence of six letters used to represent a single sound (phoneme), or a combination of sounds that do not correspond to the individual values of the letters. They occur in Irish orthography, and many of them can be analysed as a tetragraph followed by the vowels or on either side to indicate that the neighbouring consonants are palatalized ("slender"). However, not all Irish hexagraphs are analysable that way. The hexagraph , for example, represents the same sound (approximately the vowel in English "write") as the trigraph a