Keep going to the end of the queue (4)
I believe the answer is:
last
'keep going' is the definition.
(I've seen this before)
'the end of the queue' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
The remaining letters 'las' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for last that I've seen before include "Rearmost" , "Shoemaker's shape" , "Final; endure" , "` `The cobler should stick to his ....' '" , "` `Let the cobbler stick to his ....' '" .)