Pair entertaining great fondness for shore bird (6)
I believe the answer is:
plover
'for shore bird' is the definition.
(plover is a kind of shore bird)
'pair entertaining great fondness' is the wordplay.
'pair' becomes 'pr' (abbreviation).
'entertaining' means one lot of letters goes inside another.
'great fondness' becomes 'love' (I've seen this before. I am not sure about the 'great' bit.).
'pr' going around 'love' is 'PLOVER'.
Can you help me to learn more?
(Other definitions for plover that I've seen before include "Shore bird with long pointed wings" , "Lapwing-like bird" , "Wader" , "Lapwing, for example" , "Short-billed shore bird" .)