The "evil spirit" may derive rather from rby vb. #3, i.e. "one lying in wait". But we are more inclined to believe that all examples are ultimately due to a misreading of mrzby in square script. For the other opinion see Morgenster and Ford, BSOAS 80.2(2017):212f.
Page refs. in other dictionaries: DJBA: 705aDrower/Macuch: 253b