Extended howling’s forced weak leader to flee (7)
I believe the answer is:
longish
'forced weak leader to flee' is the definition.
I can't tell whether this definition defines the answer.
'extended howling's' is the wordplay.
'extended' becomes 'long' (extended can mean longer than usual).
'howling's' becomes 'ish' (I can't explain this - if you can you should give a lot more credence to this answer).
'long'+'ish'='LONGISH'
Can you help me to learn more?
(Other definitions for longish that I've seen before include "Fairly lengthy" , "Fairly extended" .)