Dictionary of Medieval Names
from European Sources

Idalia f. A hypocoristic of any of various names beginning with Old Frankish idal, a lengthening of Old Frankish id, of uncertain origin but perhaps related to Old Icelandic 'work, business, occupation, per Morlet.

France
Latin
c823 Idalia (nom) irminon-vol2 29, Palatiolum
Cite as: S.L. Uckelman. "Idalia". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Idalia.