Pressed De Niro to perform (6)
I believe the answer is:
ironed
'pressed' is the definition.
(similar in meaning)
'de niro to perform' is the wordplay.
'to perform' is an anagram indicator (I've seen 'performed' mean this).
'de'+'niro'='deniro'
'deniro' is an anagram of 'IRONED'.
(Other definitions for ironed that I've seen before include "Smoothed with hot metal" , "flattened" , "prepared for 23 [WARDROBE] ?" , "Smoothed with domestic device" , "Given a press" .)