Daniels introduced two neologisms for categories of scripts, first published in 1990: abjad (an "alphabet" with no vowel letters, derived from the Arabic term) and abugida (a system of consonant+vowel base syllables modified to denote other or no vowels, derived from the Ethiopic term per a suggestion from Wolf Leslau).[5][6]
^Peter T. Daniels and William Bright: The World's Writing Systems. Oxford University Press. ISBN0-19-507993-0
^Daniels, P. (1990). Fundamentals of Grammatology. Journal of the American Oriental Society, 110(4), 727-731. doi:10.2307/602899: "We must recognize that the West Semitic scripts constitute a third fundamental type of script, the kind that denotes individual consonants only. It cannot be subsumed under either of the other terms. A suitable name for this type would be "alephbeth," in honor of its Levantine origin, but this term seems too similar to "alphabet" to be practical; so I propose to call this type an "abjad," [Footnote: I.e., the alif-ba-jim order familiar from earlier Semitic alphabets, from which the modern order alif-ba-ta-tha is derived by placing together the letters with similar shapes and differing numbers of dots. The abjad is the order in which numerical values are assigned to the letters (as in Hebrew).] from the Arabic word for the traditional order6 of its script, which (unvocalized) of course falls in this category... There is yet a fourth fundamental type of script, a type recognized over forty years ago by James-Germain Fevrier, called by him the "neosyllabary" (1948, 330), and again by Fred Householder thirty years ago, who called it "pseudo-alphabet" (1959, 382). These are the scripts of Ethiopia and "greater India" that use a basic form for the specific syllable consonant + a particular vowel (in practice always the unmarked a) and modify it to denote the syllables with other vowels or with no vowel. Were it not for this existing term, I would propose maintaining the pattern by calling this type an "abugida," from the Ethiopian word for the auxiliary order of consonants in the signary."