Glaðr

Glaðr (sometimes anglicised as Glad, Gladr, or Glath) is a horse in Nordic mythology. It is listed as among the horses of the Æsir ridden to Yggdrasil each morning in the Poetic Edda. The Prose Edda specifically refers to it as one of the horses of the Day (likely Dagr), along with Skinfaxi.

Etymology
The Old Norse word Glaðr translates to English as "glad one", "shining one", or "bright one". It is derived from the adjective *gladaz, meaning "bright", "shining" or "cheerful", and is cognate with modern English "glad".

Grímnismál
In the poem Grímnismál of the Poetic Edda, Glaðr is one of the horses ridden by the gods as they go daily to Yggdrasil:

Gylfaginning
A similar list of horses is given in Gylfaginning in the Prose Edda:

Skáldskaparmál
The Skáldskaparmál describes Glaðr being one of the horses of the day, or Dagr, along with Skinfaxi.

The Þulur list Glaðr along with other horses such as Blóðughófi, Grani and Árvakr.

Háttatal
In Háttatal, Glaðr is used as a heiti for a horse in a kenning for a ship.