Could also be taken as a combination of May and Belle, in which case it means "beautiful hawthorn flower", "beautiful (month of) May", or even "great beauty", depending on which meaning of the name May is used. ("Great beauty" is taken from Belle, French for "beautiful", and Maia, from which May is derived, Latin for "great".) To me, Mabel and Maybelle are different names, because I pronounce Mabel as "MAY-bul" and Maybelle as "MAY-bel".