Definitions for yggdrasilˈɪg drə sɪl, ˈüg-
Random House Webster's College Dictionary
Ygg•dra•silˈɪg drə sɪl, ˈüg-(n.)
(in Norse myth) a great ash tree situated in the center of the world, with roots extending into Asgard and Niflheim.
(Norse mythology) a huge ash tree whose roots and branches hold the earth and Heaven and Hell together
The World Tree in Norse mythology. The great ash tree.
Origin: From Yggdrasill. Commonly accepted as being composed yggr + drasill, where “steed” refers to a hanging tree.
The Nuttall Encyclopedia
. See Iggdrasil.