Bloody -- as hens' teeth? (4)
I believe the answer is:
rare
'bloody' is the definition.
(I know that bloody can be written as rare)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rare that I've seen before include "having few matches?" , "Seldom encountered" , "Ben Jonson was considered so" , "Very scarce, like undercooked steak" , "not often spotted" .)