Weak without salt, not likely to go (9)
I believe the answer is:
unsalable
'not likely to go' is the definition.
I can't tell whether this defines the answer.
'weak without salt' is the wordplay.
'weak' becomes 'unable' (similar in meaning).
'without' is an insertion indicator ('without' can be similar in meaning to 'outside').
'salt' becomes 'sal' (I've seen this in other clues).
'unable' enclosing 'sal' is 'UNSALABLE'.
Can you help me to learn more?
(Another definition for unsalable that I've seen is " Not to be shifted".)