Ingigerd f. Old Icelandic ing(i), of uncertain origin but perhaps identical with the god name Ing or Yngvi, also of uncertain origin + Old Icelandic gerðr 'enclosure, protection; yard, garden'.
The name of an 11th C grand princess consort of Kiev and saint, an 11th C queen consort of Denmark and Sweden, and a 13th C queen consort of Sweden.