Up A Gum Tree
With most phrases it is the origin rather than the meaning that is in doubt. ‘Up a gum tree’ has several meanings. The most commonly used is ‘in great difficulties’. Other meanings are ‘in a state of contentment’ or ‘with great speed’.
The phrase originated as ‘like a possum up a gum tree’ and interpretations of this account for the variety of meaning. The allusion is to possums escaping up trees after being chased by hounds. Depending on one’s point of view the possum could be said to be either in difficulty as it couldn’t escape, relaxing contentedly because the hounds couldn’t catch it – either way it would probably have shown a good turn of speed up the tree in the first place.
Gum tree is the common name for the Eucalyptus in Australia and the Black Gum or Tupelo in North America.