Æther

Æther's Last.fm

AETHER (E’ther) n. Greek Mythology
1. The upper regions of space; the clear sky; the heavens.
2. The fifth and highest element after air, earth, fire and water; believed to be the substance composing all heavenly bodies.

The letter 'Æ' is a grapheme which in the Old English Latin Alphabet is named 'æsc,' which means 'ash-tree' and the name comes from an Anglo-Saxon rune.