Vegetarian, bright-eyed and bushy-tailed (8)
I believe the answer is:
squirrel
'vegetarian' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for squirrel that I've seen before include "Magpie" , "Tree-climbing rodent with bushy tail, red or grey" , "Nut-gathering rodent" , "Tree-climbing rodent which hoards nuts" , "Grey or (rarely) red woodland creature" .)