Acclaims postscript about move up (7)
I believe the answer is:
praises
'acclaims' is the definition.
(I know this)
'postscript about move up' is the wordplay.
'postscript' becomes 'ps' (abbreviation).
'about' means one lot of letters goes inside another.
'move up' becomes 'raise' (I've seen this in another clue).
'ps' going around 'raise' is 'PRAISES'.
(Other definitions for praises that I've seen before include "Worships" , "Commends, hails" , "Extols, lauds" .)