Definition - A visual symbol, such as a letter, that is used to represent a phoneme.

1. In contrast to a glyph, which is the shape that a particular typeface gives to a particular symbol. Hence one grapheme can be represented by many glyphs.

Example -
The grapheme <f> consists of the set of letters — such as the f in fun, the ff in puffy, the gh in rough, and the ph in phone — that are used to represent the phoneme /f/.

Etymology -
The word was coined by combining the Greek graphos, writing, with the suffix -eme , as in morpheme and phoneme.

Oxford English Dictionary -
Its first citation is from 1935:
"It would clarify the issue if these units might be called ‘graphemes’."
(W. F. Twaddell, Defining Phonemes, 54 )

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