noun: A writing system for Arabic, historically also employed as a numeral system, in which there is one glyph (symbol or letter) for each consonant but vowels are not specified.
noun: (linguistics) Any writing system in which glyphs are used to represent consonants or consonantal phonemes, but not vowels.
noun: The system of abjad numerals; a numeral system in which the letters of the Arabic abjad are interpreted as numerals, typically used to enumerate lists and nested lists, as well as in numerology.
