Playfair noun. ['pleɪfɛ:] E20.
[Lyon Playfair, 1st Lord Playfair (1818-98), Brit. chemist and administrator.]
A code or cipher in which successive pairs of letters are replaced by pairs chosen in a prescribed manner from a matrix of 25 letters, usu. arranged in accordance with a keyword. Usu. more fully Playfair cipher, Playfair code, etc.

[TahlilGaran] English Dictionary ▲