Uruz

The reconstructed Proto-Germanic name of the rune ᚢ from the Elder Futhark is Ūruz, meaning "wild ox" or Ūrą meaning "water." It may have been derived from the Raetian alphabet character u, as it is similar in both form and phonetic value. The name of the corresponding letter in the Gothic alphabet is urus.

Name
The Icelandic word for "rain" and the Old English word for "aurochs" derive from two different Proto-Germanic words, ūruz and ūrą (though possibly from the same root). The Norwegian meaning "slag, slag" is less clear, but it might be a technical term from the Iron Age, derived from the word for water (cf. the Kalevala, where iron is compared to milk). In Northern Spain and Southern France, the Basque word "ura" is used for water.

Because of this, it is difficult to reconstruct a Proto-Germanic name for the Elder Futhark rune. It might have been ūruz meaning "aurochs" (see also bull cult), or ūrą meaning "water." The aurochs is preferred by authors of modern rune divination systems, but both meanings seem possible when compared to the names of other runes: "water" would be comparable to "hail" and "lake," while "aurochs" would be similar to "horse" or "elk" (although the latter name itself is uncertain). However, the Gothic alphabet seems to favour "aurochs": the letter 𐌿 u is called urus.

Rune Poems
It is mentioned in all three rune poems, and in all of them, it is called Ur, though with different meanings:

Rune Poem

Old Norwegian
ᚢ Úr er af illu jarne;
opt løypr ræinn á hjarne.

Slag comes from bad iron;
the reindeer often runs over frozen snow.

Old Icelandic
ᚢ Úr er skýja grátr
ok skára þverrir
ok hirðis hatr.
umbre vísi

Rain is the lament of the clouds
and the destruction of the hay harvest
and the hatred of the shepherd.

Old English
ᚢ Ur byþ anmod ond oferhyrned,
felafrecne deor, feohteþ mid hornum
mære morstapa; þæt ist modig ƿuht.

The aurochs is proud and has large horns;
it is a very wild beast and fights with its horns;
a great ranger of the moors, it is a beast of courage.