Greeting boy in doorway with present (7)
I believe the answer is:
exhibit
'present' is the definition.
(I know that present can be written as exhibit)
'greeting boy in doorway' is the wordplay.
'greeting' becomes 'hi' (hi is a kind of greeting).
'boy' becomes 'b' (abbreviation used in schools).
'in' is an insertion indicator.
'doorway' becomes 'exit' (I can't justify this - if you can you should give a lot more credence to this answer).
'hi'+'b'='hib'
'hib' going into 'exit' is 'EXHIBIT'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for exhibit that I've seen before include "Publicly display" , "Something on show" , "Object on formal public display" , "Show - piece of evidence in court" , "Put on show" .)