Old chief spies pulled up (7)
I believe the answer is:
archaic
'old' is the definition.
(similar in meaning)
'chief spies pulled up' is the wordplay.
'chief' becomes 'arch' (synonyms).
'spies' becomes 'CIA' (Central Intelligence Agency).
'pulled up' is a reversal indicator.
'cia' back-to-front is 'aic'.
'arch'+'aic'='ARCHAIC'
(Other definitions for archaic that I've seen before include "Antiquated" , "Very old or old-fashioned" , "Obsolete" , "Of a much earlier period" , "Ancient, no longer current" .)