Acknowledge us with late turn (6)
I believe the answer is:
salute
'acknowledge' is the definition.
(thesaurus)
'us with late turn' is the wordplay.
'with' means one lot of letters go next to another.
'turn' indicates anagramming the letters.
'us' put after 'late' is 'lateus'.
'lateus' with letters rearranged gives 'SALUTE'.
(Other definitions for salute that I've seen before include "Hail, greet" , "A greeting, often military" , "Greet in military style" , "Mark" , "Ceremonial firing of guns" .)