Estella's admirer was given it; a bird (5)
I believe the answer is:
pipit
'bird' is the definition.
(I know that Pipit is a type of oscine)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pipit that I've seen before include "Songbird with streaky brown plumage" , "Lark-like bird" , "Songbird of rock or meadow" , "Songbird of open country" , "Meadowland bird" .)