Gamble a thousand, it's just a litte bit (5)
I believe the answer is:
speck
'bit' is the definition.
(I've seen this in another clue)
'gamble a thousand' is the wordplay.
'gamble' becomes 'spec' (I've seen this before).
'a thousand' becomes 'K' (K can mean thousand, e.g. 10k).
'spec'+'k'='SPECK'
'it's just a litte' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for speck that I've seen before include "Tiny spot" , "Small particle" , "Italian ham" , "lot of fat in school?" , "Small mark" .)