Dictionary of Medieval Names
from European Sources

Placentius m. Latin placens, placentius 'pleasing, satisfying, giving pleasure'.

Cf. Pleasant.

Italy
Latin
1522x1532 Placentinus (nom) DSF p. 54, 56
Spain
Latin
954 placenti (gen) CDGH XLVII
Cite as: S.L. Uckelman. "Placentius". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Placentius.