Bet on and it will be slow (7)
I believe the answer is:
andante
'be slow' is the definition.
(similar in meaning)
'bet on and' is the wordplay.
'bet' becomes 'ante' (ante is a kind of bet).
'on' is a charade indicator (letters next to each other).
'ante' put after 'and' is 'ANDANTE'.
'it will' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for andante that I've seen before include "moving steadily" , "Moving fairly slowly" , "(Of tempo) moderately slow" , "Fairly slow movement" , "For players, rather slow" .)