Ambush; intercept (6)
I believe the answer is:
waylay
I believe this is a double definition.
'ambush' is the first definition.
(synonyms)
'intercept' is the second definition.
(I've seen this in another clue)
(Other definitions for waylay that I've seen before include "buttonhole" , "Accost" , "Lie in wait for, to talk or rob (6)" , "Intercept and detain" , "Intercept and attack" .)