Owl after small piece (7)
I believe the answer is:
shooter
'piece' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'owl after small' is the wordplay.
'owl' becomes 'hooter' (I've seen this in another clue).
'after' means one lot of letters go next to another.
'small' becomes 's' (abbreviation - e.g. clothes size).
'hooter' put after 's' is 'SHOOTER'.
Can you help me to learn more?
(Other definitions for shooter that I've seen before include "Gun (sl.)" , "Gun - ball that keeps unexpectedly low" , "one fired" , "that rolls along the ground" , "photographer?" .)