From ܡܸܚܕܵܐ (miḥdā, “at once, immediately”) + -ܝܐ (-āyā, the attributive adjective ending).
ܡܸܚܕܵܝܵܐ • (miḥdāyā) (feminine ܡܸܚܕܵܝܬܵܐ (miḥdāytā), plural ܡܸܚܕܵܝܹ̈ܐ (miḥdāyē))