Obsession shown in hunting bird with cavalry (10)
I believe the answer is:
hobbyhorse
'obsession shown in hunting' is the definition.
I can't tell whether this definition defines the answer.
'bird with cavalry' is the wordplay.
'bird' becomes 'hobby' (hobby is a kind of bird).
'with' means one lot of letters go next to another.
'cavalry' becomes 'horse' (horse cavalry is a kind of cavalry).
'hobby'+'horse'='HOBBYHORSE'
Can you help me to learn more?
(Other definitions for hobbyhorse that I've seen before include "plaything" , "Toy" .)