Medium-sized wading bird with a small head (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
ruff
(Other definitions for ruff that I've seen before include "Extravagant collar" , "Starched frill; fish" , "Jacobean neckwear" , "Starched neck frill" , "Male sandpiper" .)