Line up on left coming back, he cries (6)
I believe the answer is:
yeller
'back he cries' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'line up on left' is the wordplay.
'line' becomes 'ley' (as in ley lines).
'up' becomes 'rel' (I can't explain this - if you can you should believe this answer much more).
'on' is a charade indicator (letters next to each other).
'left' says the letters should be written in reverse.
'ley' put after 'rel' is 'relley'.
'relley' in reverse letter order is 'YELLER'.
'coming' is the link.
Can you help me to learn more?
(Another definition for yeller that I've seen is " one making a lot of noise".)