* It's a regional or colloquial term: There might be a specific region or community where "foolbird" has a particular meaning.
* It's a made-up word: Someone might have invented the term for a specific purpose, like a character in a story or a joke.
* It's a misspelling: Perhaps the intended word is something similar, like "foolbird" instead of "foolbird."
To better understand what you're looking for, please provide more context. For example:
* Where did you encounter this term?
* What was the situation or context around its use?
* What were you hoping to find out about "foolbird"?
With more information, I can try to help you understand its meaning.