Scholarly opinions regarding the precise meaning of the name Yggdrasill vary, particularly on the issue of whether Yggdrasill is the name of the tree itself, or if only the full term askr Yggdrasil refers specifically to the tree. Yggdrasill means "Ygg's horse", "Yggr" is one of Odin's many names, and according to this, askr Yggdrasils would be viewed as the world-tree upon which the "horse of the highest god is bound".[1]
The generally accepted etymology of the name is that Yggdrasill means "Odin's horse", which means "tree", and that the reason behind the name "Odin's horse" lies in the notion of gallows as "the horse of the hanged", and, according to this notion, the tree would then be the gallows in which Odin hanged during his self-sacrifice described in the Poetic Edda poem Hávamál. Both of these etymologies rely on a presumed but unattested *Yggsdrasill.[1]
A third interpretation by F. Detter is that the name Yggdrasill refers to the word Yggr ("terror"), yet not in reference to the Odinic name, and so Yggdrasill would then mean "tree of terror, gallows". F. R. Schröder has proposed a fourth etymology where yggdrasill means "yew pillar", deriving yggia from *igwja (meaning "yew-tree"), and drasill from *dher- (meaning "support").[1]