We're at a loose end very little (3)
I believe the answer is:
wee
'very little' is the definition.
(I've seen this in another clue)
'we're at a loose end' is the wordplay.
'we're' becomes 'we' (I can't justify this - if you can you should give a lot more credence to this answer).
'at' means one lot of letters go next to another.
'end' indicates one should take the final letters.
The last letter of 'loose' is 'e'.
'we'+'e'='WEE'
Can you help me to learn more?
(Other definitions for wee that I've seen before include "number one" , "Jimmy" , "(Scots) little" , "Minute" , "It's small in Scotland" .)