Ehwaz

Ehwaz is the reconstructed Proto-Germanic name of the Elder Futhark e-rune ᛖ, which means "horse" (related to Latin equus, Gaelic epos, Tocharian B yakwe, Sanskrit aśva, Avestan aspa, and Old Irish ech). In the Anglo-Saxon futhorc, it is continued as ᛖ eh (actually eoh, but written without the diphthong to avoid confusion with ᛇ ēoh "yew").

The Proto-Germanic vowel system was asymmetrical and unstable. The distinction between the long vowels, expressed by ᛖ e and ᛇ ï (sometimes transcribed as ē1 and ē2), was lost. The Younger Futhark does not continue this distinction, as a letter expressing e is completely absent. The Anglo-Saxon futhorc retained all the older futhorc runes, assigning new phonetic values to the redundant ones, with futhorc ēoh representing a diphthong.

In the case of the Gothic alphabet, where the names of the runes were applied to letters derived from the Greek alphabet, the letter 𐌴 e was also called aíƕus "horse" (note that in Gothic orthography, ⟨aí⟩ represents the monophthong /e/).

Anglo-Saxon Rune Poem
The Anglo-Saxon Rune Poem has:

ᛖ Eh byþ für eorlum æþelinga ƿyn,
hors hofum ƿlanc, ðær him hæleþ ymb[e]
ƿelege on ƿicgum ƿrixlaþ spræce
und biþ unstyllum æfre frofur.

"The horse is a joy for princes, a noble delight,
A steed in the pride of its hooves,
When wealthy men ride and speak to it;
And it is always a source of comfort for the restless."