Not fitting into any recognized category; belonging to neither one group nor the other. Also expressed as 'neither fish nor flesh' or 'neither fish, flesh, nor fowl.'
Examples:
- They felt he was neither fish nor fowl — not qualified to lead the department, yet not appropriate to work as a staff member either.
Origin: First recorded in John Heywood's 1546 proverb collection
Synonyms: neither fish nor flesh