Lowly enemy in a period between actions? (8)
I believe the answer is:
meantime
'a period between actions?' is the definition.
'lowly enemy' is the wordplay.
'lowly' becomes 'mean'.
'enemy' becomes 'time' (reference to the phrase 'time is the enemy').
'mean'+'time'='MEANTIME'
'in' acts as a link.
(Other definitions for meantime that I've seen before include "Intervening period" , "interval" , "For the moment" , "interim?" .)