Dictionary of Medieval Names
from European Sources

Meinsent f. Old High German megin, magan 'strength, might, power ' + Old Saxon swīth, Gothic swinþs from Proto-Germanic *swinþaz 'strong'.

France
Latin
1147 Meinsende (abl) clairvaux-12thc 18
Cite as: S.L. Uckelman. "Meinsent". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Meinsent.