Left the dog out something mushy (4)
I believe the answer is:
pulp
'something mushy' is the definition.
I can't tell whether this definition defines the answer.
'left the dog out' is the wordplay.
'left' becomes 'l' (common abbreviation).
'the dog' becomes 'pup' (I've seen this in other clues).
'out' indicates putting letters inside.
'l' inserted into 'pup' is 'PULP'.
Can you help me to learn more?
(Other definitions for pulp that I've seen before include "recycle paper" , "Soft fleshy part of a fruit" , "Soft moist mass, may be crushed" , "Crush" , "Soft plant tissue" .)