Just move by earl (6)
I believe the answer is:
barely
'just' is the definition.
(barely can mean only just)
'move by earl' is the wordplay.
'move' indicates anagramming the letters (I've seen 'moves' mean this).
'by'+'earl'='byearl'
'byearl' anagrammed gives 'BARELY'.
(Other definitions for barely that I've seen before include "By a small margin" , "Hardly" , "as Godiva rode?" , "Just about, nothing to spare" , "just a short while before" .)