Dictionary of Medieval Names
from European Sources

Marcswith f. Old High German marka 'march; fortified area along a border' + Old Saxon swīth, Gothic swinþs from Proto-Germanic *swinþaz 'strong'.

Germany
Latin
822x875 Mercsuit (abl) TradCorb §82
Cite as: S.L. Uckelman. "Marcswith". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Marcswith.