Dictionary of Medieval Names
from European Sources

Bonjohn m. Latin bonus 'good, kind, right, pleasant; valid, useful, healthy' + John.

Italy
Latin
1285 Boniohannis (gen) Perugia1285 p. 154; 1348 Bonianni (gen) INP 13
Italian
1513x1521 Boniohanni LeoX p. 17
Switzerland
Latin
1436 Boni Iohannis (gen) MHCG2 209, Bono Iohanne (abl) ibid. 209
Cite as: S.L. Uckelman. "Bonjohn". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2018, no. 1. http://dmnes.org/2018/1/name/Bonjohn.