We're at a loose end, just a little (3)
I believe the answer is:
wee
'a little' is the definition.
(I've seen this before)
'we're at a loose end' is the wordplay.
'we're' becomes 'we' (I can't justify this - if you can you should believe this answer much more).
'at' says to put letters next to each other.
'end' suggests the final letters.
The final letter of 'loose' is 'e'.
'we'+'e'='WEE'
'just' is the link.
Can you help me to learn more?
(Other definitions for wee that I've seen before include "Small, like Willy Winkie" , "Informally tiny as in Scotland" , "Little or tiny in Scotland" , "Mini in Glasgow?" , "(Scots) little" .)