A high-level similarity between different things or processes. Metaphors can reflect a deep structural resonance or merely a superficial resemblance; cultural assumptions often rest on metaphors, which can be both incisive and misleading, valuable and dangerous.
Gareth Southgate the Tartan Army's 1996 player of the year remained strangely tight-lipped on Beck's penalty howler against the French but rabbited on like a budgie (feel free, Charlie Nick, if you'd like to borrow that mixed metaphor)about the 35 degree heat and how England would struggle to cope.
It could be the Scots who swing it for Tony Blair but we should not be led down the garden path by this particular red herring, if you'll pardon the mixed metaphor. Scottish students sometimes head south for university education and they would be affected by fees.
So let's review: A mixed metaphor is a combination of two figures of speech that unintentionally results in an incongruous or impossible image: "The proposal is on the back burner in a holding pattern." "It' s the whole kettle of fish in a nutshell." Or ponder this classic student blooper: "A virgin forest is a place where the hand of man has never set foot."
Quick refresher: A mixed metaphor is a combination of figures of speech that creates an incongruous or absurd image: "He's out of the frying pan and into hot water." "The sacred cows have come home to roost." "His victory is a springboard to rekindle his campaign." As these examples demonstrate, the colliding tropes are often idiomatic expressions or cliches.