(ˈ)bī+ adjective
Etymology: bi- (I) + literal
1. : consisting of or employing two letters or types of letters: as
a. : having two root consonants
Semitic biliteral nouns
b. : written in two different alphabets
2. cryptography
a. : composed of or employing a cover text in which two letter forms or type faces are used in significant combinations — see bacon biliteral cipher
b. : representing one letter by two