Dictionary of Medieval Names
from European Sources

Brunissende f. Old High German brūn 'brown', from Proto-Germanic brūnaz 'grey, brown' or Old High German brunnia 'breast plate' + Old Saxon swīth, Gothic swinþs from Proto-Germanic *swinþaz 'strong'.

Spain
Catalan
1248 Brunissen RusGeb p. 271
Cite as: S.L. Uckelman. "Brunissende". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Brunissende.