Love alluring woman no end: time for action? (4,4)
I believe the answer is:
zero hour
'time for action?' is the definition.
(time when a military organisation begins)
'love alluring woman no end' is the wordplay.
'love' becomes 'zero' (love is zero in tennis).
'alluring woman' becomes 'houri' (beautiful young woman in Islamic paradise).
'no end' means to remove the last letter.
'houri' with its last letter taken away is 'hour'.
'zero'+'hour'='ZERO HOUR'
(Other definitions for zero hour that I've seen before include "When battle is due to commence" , "Time action begins" , "Kick-off" , "Time to begin military operation" , "when attack begins?" .)