Hide jam without hesitation (4,4)

I believe the answer is:

lock away

I'm a little stuck... Click here to teach me more about this clue!

'hide' is the definition.
(I've seen this before)

'jam without hesitation' is the wordplay.
'jam' becomes 'lock' (I can't justify this - if you can you should believe this answer much more).
'without hesitation' becomes 'away' (I've seen this in another clue).
'lock'+'away'='LOCK AWAY'

Can you help me to learn more?

(Another definition for lock away that I've seen is " Hide safely".)

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app