Dictionary of Medieval Names
from European Sources

Isolde f. Of uncertain origin, either Celtic or Germanic. If Germanic, then it is likely Old High German īs 'ice' + Old High German hiltja 'battle'.

The name of the main female character in the legends and lays of Tristan and Isolde.

The Middle English vernacular form Isoude appears in the matronymic byname of Johannes Isoude, 1318, PSS-CXIV 4b.

England
Latin
1279–80 Isolda (nom) WaHR-SK p. 60; 1296 Isolde (dat) RCS-1 p. 93a; 1331 Isoude (gen) PSS-CXIV 4e; 1340xc1450 Isolda (nom) CovGuild-1 p. 16; 1379 Isolda (nom) WRYPT1 p. 19, Isselda (nom) ibid. p. 13; 1381 Isolda (nom) FenPT-2 p. 8, Isoude (nom) Suffolk1381 p. 110; 1423 Isotæ (gen) WillsInv L
Early Modern English
1559 Isote DEmar-vol1 p. 80; 1590 Isett DEmar-vol2 p. 22; 1595 Iset ibid. p. 30; 1597 Iset ibid. p. 36, Isett ibid. p. 35; 1599 Isett ibid. p. 40
Cite as: J. Uckelman, S.L. Uckelman. "Isolde". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Isolde.