Ace of Spies, speaking in an ironic way (5)
I believe the answer is:
wryly
'ace of spies speaking in an' is the definition.
I can't judge whether this definition defines the answer.
'ironic way' is the wordplay.
'ironic' becomes 'wry' (synonyms).
'way' becomes 'ly' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'wry'+'ly'='WRYLY'
Can you help me to learn more?
(Other definitions for wryly that I've seen before include "How mockers regard" , "sardonic fashion" .)